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class="button action backdrop" aria-label="Collapse sidebar"><span class="button-wrap"></span></button><nav aria-label="Related Topics" class="sidebar-inner"><header class="sidebar-actions"><section class="sidebar-filter-container"><div class="sidebar-filter "><label id="sidebar-filter-label" class="sidebar-filter-label" for="sidebar-filter-input"><span class="icon icon-filter"></span><span class="visually-hidden">Filter sidebar</span></label><input id="sidebar-filter-input" autoComplete="off" class="sidebar-filter-input-field false" type="text" placeholder="Filter" value=""/><button type="button" class="button action has-icon clear-sidebar-filter-button"><span class="button-wrap"><span class="icon icon-cancel "></span><span class="visually-hidden">Clear filter input</span></span></button></div></section></header><div class="sidebar-inner-nav"><div class="in-nav-toc"><div class="document-toc-container"><section class="document-toc"><header><h2 class="document-toc-heading">In diesem Artikel</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#probieren_sie_es_aus">Probieren Sie es aus</a></li><li class="document-toc-item "><a class="document-toc-link" href="#syntax">Syntax</a></li><li class="document-toc-item "><a class="document-toc-link" href="#beschreibung">Beschreibung</a></li><li class="document-toc-item "><a class="document-toc-link" href="#beispiele">Beispiele</a></li><li class="document-toc-item "><a class="document-toc-link" href="#spezifikationen">Spezifikationen</a></li><li class="document-toc-item "><a class="document-toc-link" href="#browser-kompatibilität">Browser-Kompatibilität</a></li><li class="document-toc-item "><a class="document-toc-link" href="#siehe_auch">Siehe auch</a></li></ul></section></div></div><div class="sidebar-body"> <ol> <li class="section"><a href="/de/docs/Web/JavaScript">JavaScript</a></li> <li class="section">Tutorials</li> <li class="toggle"> <details> <summary>Komplette Anfänger</summary> <ol> <li><a href="/de/docs/Learn/Getting_started_with_the_web/JavaScript_basics">JavaScript-Grundlagen</a></li> <li><a href="/de/docs/Learn/JavaScript/First_steps">Erste Schritte in JavaScript</a></li> <li><a href="/de/docs/Learn/JavaScript/Building_blocks">JavaScript-Bausteine</a></li> <li><a href="/de/docs/Learn/JavaScript/Objects">Einführung in JavaScript-Objekte</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>JavaScript-Handbuch</summary> <ol> <li><a href="/de/docs/Web/JavaScript/Guide/Introduction">Einführung</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Grammar_and_types">Grammatik und Typen</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Control_flow_and_error_handling">Steuerfluss und Fehlerbehandlung</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Loops_and_iteration">Schleifen und Iteration</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Functions">Funktionen</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Expressions_and_operators">Ausdrücke und Operatoren</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Numbers_and_dates">Zahlen und Daten</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Text_formatting">Textformatierung</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Regular_expressions">Reguläre Ausdrücke</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Indexed_collections">Indexierte Sammlungen</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Keyed_collections">Gekennzeichnete Sammlungen</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Working_with_objects">Arbeiten mit Objekten</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Using_classes">Verwendung von Klassen</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Using_promises">Verwendung von Promises</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Typed_arrays">Typisierte Arrays in JavaScript</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Iterators_and_generators">Iteratoren und Generatoren</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Meta_programming">Metaprogrammierung</a></li> <li><a href="/de/docs/Web/JavaScript/Guide/Modules">JavaScript-Module</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>Mittelstufe</summary> <ol> <li><a href="/de/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks">Client-seitige JavaScript-Frameworks</a></li> <li><a href="/de/docs/Learn/JavaScript/Client-side_web_APIs">Client-seitige Web-APIs</a></li> <li><a href="/de/docs/Web/JavaScript/Language_overview">Sprachübersicht</a></li> <li><a href="/de/docs/Web/JavaScript/Data_structures">JavaScript-Datenstrukturen</a></li> <li><a href="/de/docs/Web/JavaScript/Equality_comparisons_and_sameness">Gleichheitsvergleiche und Gleichheit</a></li> <li><a href="/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties">Aufzählbarkeit und Eigentum von Eigenschaften</a></li> <li><a href="/de/docs/Web/JavaScript/Closures">Closures</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>Fortgeschritten</summary> <ol> <li><a href="/de/docs/Web/JavaScript/Inheritance_and_the_prototype_chain">Vererbung und die Prototypenkette</a></li> <li><a href="/de/docs/Web/JavaScript/Memory_management">Speicherverwaltung</a></li> <li><a href="/de/docs/Web/JavaScript/Event_loop">Konkurrenzmodell und Ereignisschleife</a></li> </ol> </details> </li> <li class="section"><a href="/de/docs/Web/JavaScript/Reference">Referenzen</a></li> <li class="toggle"> <details> <summary>Eingebaute Objekte</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects">Standard eingebaute Objekte</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/AggregateError">AggregateError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Array">Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncFunction">AsyncFunction</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncGenerator">AsyncGenerator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncGeneratorFunction">AsyncGeneratorFunction</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncIterator">AsyncIterator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Atomics">Atomics</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/BigInt">BigInt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/BigInt64Array">BigInt64Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/BigUint64Array">BigUint64Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Boolean">Boolean</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Date">Date</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/decodeURI">decodeURI()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent">decodeURIComponent()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/encodeURI">encodeURI()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent">encodeURIComponent()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Error">Error</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/escape">escape()</a><abbr class="icon icon-deprecated" title="Veraltet. Nicht für neue Websites verwenden."> <span class="visually-hidden">Veraltet</span> </abbr></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/eval">eval()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/EvalError">EvalError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry">FinalizationRegistry</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Float16Array">Float16Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Float32Array">Float32Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Float64Array">Float64Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Function">Function</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Generator">Generator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/GeneratorFunction">GeneratorFunction</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/globalThis">globalThis</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Infinity">Infinity</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Int16Array">Int16Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Int32Array">Int32Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Int8Array">Int8Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/InternalError">InternalError</a><abbr class="icon icon-nonstandard" title="Nicht standardisiert. Überprüfen Sie die Unterstützung in verschiedenen Browsern, bevor Sie es verwenden."> <span class="visually-hidden">Nicht standardisiert</span> </abbr></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Intl">Intl</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/isFinite">isFinite()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/isNaN">isNaN()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Iterator">Iterator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/JSON">JSON</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Map">Map</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Math">Math</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/NaN">NaN</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Number">Number</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object">Object</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/parseFloat">parseFloat()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/parseInt">parseInt()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Promise">Promise</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Proxy">Proxy</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/RangeError">RangeError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError">ReferenceError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Reflect">Reflect</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/RegExp">RegExp</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Set">Set</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer">SharedArrayBuffer</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/String">String</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Symbol">Symbol</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError">SyntaxError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/TypeError">TypeError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array">Uint16Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array">Uint32Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array">Uint8Array</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Uint8ClampedArray">Uint8ClampedArray</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/undefined">undefined</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/unescape">unescape()</a><abbr class="icon icon-deprecated" title="Veraltet. Nicht für neue Websites verwenden."> <span class="visually-hidden">Veraltet</span> </abbr></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/URIError">URIError</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/WeakMap">WeakMap</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/WeakRef">WeakRef</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/WeakSet">WeakSet</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>Ausdrücke und Operatoren</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Operators">Ausdrücke und Operatoren</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Addition">Addition (+)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Addition_assignment">Addition Assignment (+=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Assignment">Zuweisung (=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/async_function">async function expression</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/async_function*">async function* Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/await">await</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_AND">Bitweises UND (&)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_AND_assignment">Bitweise UND-Zuweisung (&=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT">Bitweise NOT (~)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_OR">Bitweises Oder (|)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_OR_assignment">Bitweises OR-Zuweisung (|=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR">Bitweises XOR (^)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR_assignment">Bitweises XOR-Zuweisung (^=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/class">Klassenausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Comma_operator">Komma-Operator (,)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Conditional_operator">Bedingungsoperator (ternärer Operator)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Decrement">Decrement (--)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/delete">delete</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment">Destructuring-Zuweisung</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Division">Division (/)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Division_assignment">Division assignment (/=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Equality">Gleichheit (==)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Exponentiation">Potenzierung (**)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Exponentiation_assignment">Exponentiation-Zuweisung (**=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/function">function expression</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/function*">function* Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Greater_than">Greater than (>)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Greater_than_or_equal">Greater than or equal (>=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Grouping">Gruppierungsoperator ( )</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/import.meta">import.meta</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/import">import()</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/in">in</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Increment">Increment (++)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Inequality">Inequality (!=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/instanceof">instanceof</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Left_shift">Left shift (<<)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Left_shift_assignment">Left shift assignment (<<=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Less_than">Less than (<)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Less_than_or_equal">Less than or equal (<=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Logical_AND">Logisches UND (&&)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment">Logical AND assignment (&&=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Logical_NOT">Logisches NICHT (!)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Logical_OR">Logical OR (||)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment">Logische ODER-Zuweisung (||=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Multiplication">Multiplication (*)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Multiplication_assignment">Multiplikationszuweisung (*=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/new">new</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/new.target">new.target</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/null">null</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_assignment">Nullish coalescing assignment (??=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing">Nullish coalescing-Operator (??)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Object_initializer">Object initializer</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Operator_precedence">Operatorpriorität</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Optional_chaining">Optional Chaining (?.)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Property_accessors">Property accessors</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Remainder">Remainder (%)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Remainder_assignment">Remainder-Zuweisung (%=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Right_shift">Rechtsschiebung (>>)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Right_shift_assignment">Right shift assignment (>>=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Spread_syntax">Spread-Syntax (...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Strict_equality">Strikte Gleichheit (===)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Strict_inequality">Strikte Ungleichheit (!==)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Subtraction">Subtraction (-)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Subtraction_assignment">Subtraction assignment (-=)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/super">super</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/this">this</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/typeof">typeof</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Unary_negation">Unäre Negation (-)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Unary_plus">Unary plus (+)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift">Unsigned right shift (>>>)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment">Unsigned right shift assignment (`>>>=`)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/void">void operator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/yield">yield</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Operators/yield*">yield*</a></li></ol> </details> </li> <li class="toggle"> <details open=""> <summary>Anweisungen und Deklarationen</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Statements">Statements und Deklarationen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/async_function">async function</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/async_function*">async function*</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/block">Block Statement</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/break">break</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/class">class</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/const">const</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/continue">continue</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/debugger">debugger</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/do...while">do...while</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/Empty">Empty Statement</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/export">export</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/Expression_statement">Expression statement</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/for">for</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/for-await...of">for await...of</a></li><li><em><a href="/de/docs/Web/JavaScript/Reference/Statements/for...in" aria-current="page">for...in</a></em></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/for...of">for...of</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/function">function</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/function*">function*</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/if...else">if...else</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/import">import</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/label">Labelierte Anweisung</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/let">let</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/return">return</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/switch">switch</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/throw">throw</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/try...catch">try...catch</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/var">var</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/while">while</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Statements/with">with</a><abbr class="icon icon-deprecated" title="Veraltet. Nicht für neue Websites verwenden."> <span class="visually-hidden">Veraltet</span> </abbr></li></ol> </details> </li> <li class="toggle"> <details> <summary>Funktionen</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Functions">Functions</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/Arrow_functions">Pfeilfunktionen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/Default_parameters">Default parameters</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/get">get</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/Method_definitions">Methodendefinitionen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/rest_parameters">Rest-Parameter</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/set">set</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Functions/arguments">Das arguments Objekt</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>Klassen</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Classes">Klassen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/constructor">constructor</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/extends">extends</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/Private_properties">Private properties</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/Public_class_fields">Public class fields</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/static">static</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks">Statische Initialisierungsblöcke</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>Reguläre Ausdrücke</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions">Regular expressions</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Backreference">Backreference: \1, \2</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Capturing_group">Capturing group: (...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape">Zeichenklassen-Escape: \d, \D, \w, \W, \s, \S</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_class">Zeichenklasse: [...], [^...]</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape">Zeichen-Escape: \n, \u{...}</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Disjunction">Disjunktion: |</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Input_boundary_assertion">Input-Bereichs-Assertion: ^, $</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Literal_character">Literalzeichen: a, b</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Lookahead_assertion">Lookahead-Assertion: (?=...), (?!...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Lookbehind_assertion">Lookbehind Assertion: (?<=...), (?<!...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Modifier">Modifikator: (?ims-ims:...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Named_backreference">Benannte Rückreferenz: \k<name></a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Named_capturing_group">Named capturing group: (?<name>...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Non-capturing_group">Nicht erfassende Gruppe: (?:...)</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Quantifier">Quantifier: *, +, ?, {n}, {n,}, {n,m}</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape">Unicode-Zeichenklassenescapes: \p{...}, \P{...}</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Wildcard">Wildcard: .</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Regular_expressions/Word_boundary_assertion">Wortgrenzen-Assertion: \b, \B</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>Fehler</summary> <ol><li><a href="/de/docs/Web/JavaScript/Reference/Errors">JavaScript-Fehlerreferenz</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Promise_any_all_rejected">AggregateError: Kein Promise in Promise.any wurde aufgelöst</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Property_access_denied">Fehler: Zugriff verweigert auf Eigenschaft "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Too_much_recursion">InternalError: zu viel Rekursion</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Not_a_valid_code_point">RangeError: argument ist kein gültiger Codepunkt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/BigInt_division_by_zero">RangeError: BigInt-Division durch Null</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/BigInt_negative_exponent">RangeError: BigInt negative exponent</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Form_must_be_one_of">RangeError: form muss einer von 'NFC', 'NFD', 'NFKC' oder 'NFKD' sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_array_length">RangeError: invalid array length</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_date">RangeError: invalid date</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Precision_range">RangeError: precision liegt außerhalb des zulässigen Bereichs</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_radix">RangeError: radix muss eine ganze Zahl sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Resulting_string_too_large">RangeError: repeat count muss kleiner als unendlich sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Negative_repetition_count">RangeError: repeat count must be non-negative</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_be_converted_to_BigInt_because_it_isnt_an_integer">RangeError: x kann nicht in BigInt konvertiert werden, da es keine ganze Zahl ist</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Not_defined">ReferenceError: "x" ist nicht definiert</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Undeclared_var">ReferenceError: Zuordnung zu einer nicht deklarierten Variable "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_access_lexical_declaration_before_init">ReferenceError: kann auf lexikalische Deklaration 'X' vor der Initialisierung nicht zugreifen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Deprecated_caller_or_arguments_usage">ReferenceError: veraltete Verwendung von caller oder arguments</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Super_not_called">ReferenceError: 'super' Konstruktor muss vor der Verwendung von 'this' im Konstruktor der abgeleiteten Klasse aufgerufen werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Super_called_twice">ReferenceError: super() zweimal im abgeleiteten Klassenkonstruktor aufgerufen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_strict_arguments_eval">SyntaxError: 'arguments'/'eval' können im Strict-Mode-Code nicht definiert oder zugewiesen werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_literal">SyntaxError: "0"-präfixierte Oktalliterale sind veraltet</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Strict_non_simple_params">SyntaxError: "use strict" nicht erlaubt in Funktion mit nicht einfachen Parametern</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Reserved_identifier">SyntaxError: "x" ist ein reservierter Bezeichner</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_backslash_at_end_of_pattern">SyntaxError: \ am Ende des Musters</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-of_initializer">SyntaxError: Eine Deklaration im Kopf einer for-of-Schleife darf keinen Initialisierer haben</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Delete_in_strict_mode">SyntaxError: Die Anwendung des 'delete'-Operators auf einen unqualifizierten Namen ist veraltet</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Arguments_not_allowed">SyntaxError: arguments ist in Feldern nicht gültig</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_await">SyntaxError: await ist nur in async Funktionen, async Generatoren und Modulen gültig</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/await_yield_in_parameter">SyntaxError: await/yield expression kann nicht im Parameter verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_use_nullish_coalescing_unparenthesized">SyntaxError: `??` kann nicht ohne Klammern innerhalb von `||` und `&&`-Ausdrücken verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_character_class_escape_in_class_range">SyntaxError: Zeichenklassen-Escape kann nicht im Klassenbereich im regulären Ausdruck verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_continue">SyntaxError: continue muss innerhalb einer Schleife sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_duplicate_capture_group_name">SyntaxError: doppelter Name der Erfassungsgruppe im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Duplicate_parameter">SyntaxError: doppeltes formales Argument x</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer">SyntaxError: Deklarationen im Kopf einer for-in-Schleife dürfen keine Initialisierer enthalten</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Unnamed_function_statement">SyntaxError: Funktionsanweisung erfordert einen Namen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Function_label">SyntaxError: Funktionen können nicht beschriftet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Either_be_both_static_or_non-static">SyntaxError: Getter und Setter für privaten Namen #x sollten entweder beide statisch oder nicht statisch sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Getter_no_arguments">SyntaxError: Getter-Funktionen dürfen keine Argumente haben</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Identifier_after_number">SyntaxError: identifier startet direkt nach einer numerischen Literal</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Illegal_character">SyntaxError: illegales Zeichen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/import_decl_module_top_level">SyntaxError: import-Deklarationen dürfen nur auf der obersten Ebene eines Moduls erscheinen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_incomplete_quantifier">SyntaxError: unvollständiger Quantifizierer im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_assignment_left-hand_side">SyntaxError: invalid assignment left-hand side</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_BigInt_syntax">SyntaxError: Ungültige BigInt-Syntax</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_capture_group_name">SyntaxError: ungültiger Name der Erfassungsgruppe im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_char_in_class">SyntaxError: ungültiges Zeichen in Klasse in regulärem Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_class_set_operation">SyntaxError: Ungültige Klassenmengenoperation im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_decimal_escape">SyntaxError: ungültiger Dezimal-Escape in regulärem Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_identity_escape">SyntaxError: ungültige Identitätsflucht in regulärem Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_named_capture_reference">SyntaxError: ungültige benannte Referenz in regulärem Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_property_name">SyntaxError: ungültiger Eigenschaftsname im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_range_in_character_class">SyntaxError: invalid range in character class</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_group">SyntaxError: invalid regexp group</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_regexp_flag">SyntaxError: invalid regular expression flag "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_unicode_escape">SyntaxError: ungültiger Unicode-Escape in regulärem Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/JSON_bad_parse">SyntaxError: JSON.parse: Fehlerhaftes Parsing</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Label_not_found">SyntaxError: label not found</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_colon_after_property_id">SyntaxError: missing : after property id</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_argument_list">SyntaxError: missing ) after argument list</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_condition">SyntaxError: missing ) after condition</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_bracket_after_list">SyntaxError: missing ] after element list</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_function_body">SyntaxError: fehlende } nach Funktionskörper</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_property_list">SyntaxError: missing } after property list</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_initializer_in_const">SyntaxError: missing = in const declaration</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_formal_parameter">SyntaxError: missing formal parameter</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Missing_name_after_dot_operator">SyntaxError: missing name after . operator</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/No_variable_name">SyntaxError: missing variable name</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_negated_char_class_with_strings">SyntaxError: Negierte Zeichenklasse mit Strings im regulären Ausdruck</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_new_optional">SyntaxError: new-Schlüsselwort kann nicht mit einer Optionalen Kette verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_nothing_to_repeat">SyntaxError: nothing to repeat</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_numbers_out_of_order_in_quantifier">SyntaxError: numbers out of order in {} quantifier.</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_escape_sequence">SyntaxError: Oktale Escape-Sequenzen können nicht in nicht-getaggten Vorlagenliteralen oder im Strict Mode-Code verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Parameter_after_rest_parameter">SyntaxError: parameter nach Rest-Parameter</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_delete_private_fields">SyntaxError: private fields können nicht gelöscht werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Duplicate_proto">SyntaxError: Eigenschaftenname __proto__ erscheint mehr als einmal im Objektliteral</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Regex_raw_bracket">SyntaxError: Raw-Klammern sind im regulären Ausdruck mit Unicode-Flag nicht erlaubt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Redeclared_parameter">SyntaxError: redeclaration of formal parameter "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Undeclared_private_field_or_method">SyntaxError: Verweis auf nicht deklariertes privates Feld oder Methode #x</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Rest_with_default">SyntaxError: Restparameter darf keinen Standardwert haben</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_return">SyntaxError: return not in function</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Setter_one_argument">SyntaxError: Setter-Funktionen müssen ein Argument haben</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/String_literal_EOL">SyntaxError: string literal enthält einen nicht-escaped Zeilenumbruch</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_super_call">SyntaxError: super() ist nur in Konstruktoren abgeleiteter Klassen gültig</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_optional_template">SyntaxError: getaggtes Template kann nicht mit optionaler Verkettung verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Hash_outside_class">SyntaxError: Unerwartetes '#' außerhalb des Klassenkörpers verwendet</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Unexpected_token">SyntaxError: Unerwartetes Token</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_break">SyntaxError: unlabeled break muss innerhalb einer Schleife oder eines Switch sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Unparenthesized_unary_expr_lhs_exponentiation">SyntaxError: unverklammerter unärer Ausdruck kann nicht auf der linken Seite von '**' erscheinen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Bad_super_prop">SyntaxError: Verwendung von Super-Eigenschaften/-mitgliedern ist nur innerhalb von Methoden oder eval-Code innerhalb von Methoden gültig</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Deprecated_source_map_pragma">SyntaxError: Die Verwendung von //@ zur Angabe von sourceURL-Pragmas ist veraltet. Verwenden Sie stattdessen //#</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/is_not_iterable">TypeError: 'x' ist nicht iterierbar</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Unexpected_type">TypeError: "x" ist (nicht) "y"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Not_a_constructor">TypeError: "x" ist kein Konstruktor</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Not_a_function">TypeError: "x" ist keine Funktion</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/No_non-null_object">TypeError: "x" ist kein nicht-null-Objekt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Read-only">TypeError: "x" ist schreibgeschützt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/BigInt_not_serializable">TypeError: BigInt-Wert kann nicht in JSON serialisiert werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Builtin_ctor_no_new">TypeError: Der Aufruf eines eingebauten X-Konstruktors ohne new ist verboten</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Get_set_missing_private">TypeError: kann nicht auf privates Feld oder Methode zugreifen/setzen: Objekt ist nicht die richtige Klasse</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_assign_to_property">TypeError: kann Eigenschaft „x“ auf „y“ nicht zuweisen: kein Objekt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_convert_BigInt_to_number">TypeError: can't convert BigInt to number</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_convert_x_to_BigInt">TypeError: kann x nicht in BigInt konvertieren</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_define_property_object_not_extensible">TypeError: kann Eigenschaft "x" nicht definieren: "obj" ist nicht erweiterbar</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Non_configurable_array_element">TypeError: can't delete non-configurable array element</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_redefine_property">TypeError: kann nicht konfigurierbare Eigenschaft "x" neu definieren</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_set_prototype">TypeError: kann das Prototyp dieses Objekts nicht festlegen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cyclic_prototype">TypeError: can't set prototype: it would cause a prototype chain cycle</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/in_operator_no_object">TypeError: kann den 'in'-Operator nicht verwenden, um nach 'x' in 'y' zu suchen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Class_ctor_no_new">TypeError: Klassenkonstruktoren müssen mit 'new' aufgerufen werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value">TypeError: cyclic object value</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_derived_return">TypeError: abgeleiteter Klassenkonstruktor hat einen ungültigen Wert x zurückgegeben</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Private_setter_only">TypeError: getting private setter-only property</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Private_double_initialization">TypeError: Initialisierung eines Objekts zweimal ist ein Fehler bei privaten Feldern/Methoden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/invalid_right_hand_side_instanceof_operand">TypeError: ungültiger 'instanceof'-Operand 'x'</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Array_sort_argument">TypeError: invalides Array.prototype.sort Argument</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_const_assignment">TypeError: ungültige Zuweisung zu const "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Constructor_cant_be_used_directly">TypeError: Iterator/AsyncIterator-Konstruktor kann nicht direkt verwendet werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Requires_global_RegExp">TypeError: matchAll/replaceAll muss mit einem globalen RegExp aufgerufen werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/More_arguments_needed">TypeError: Mehr Argumente benötigt</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/No_properties">TypeError: null/undefined hat keine Eigenschaften</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Cant_delete">TypeError: Eigenschaft "x" ist nicht konfigurierbar und kann nicht gelöscht werden</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Reduce_of_empty_array_with_no_initial_value">TypeError: Reduce eines leeren Arrays ohne initialen Wert</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Getter_only">TypeError: Einstellung der nur-Getter-Eigenschaft "x"</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Key_not_weakly_held">TypeError: WeakSet-Schlüssel/WeakMap-Wert 'x' muss ein Objekt oder ein nicht registriertes Symbol sein</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Called_on_incompatible_type">TypeError: X.prototype.y auf inkompatiblen Typ aufgerufen</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Malformed_URI">URIError: malformed URI sequence</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Already_has_pragma">Warnung: -file- wird ein //# sourceMappingURL zugewiesen, hat aber bereits eines</a></li><li><a href="/de/docs/Web/JavaScript/Reference/Errors/Stmt_after_return">Warnung: unerreichbarer Code nach return-Anweisung</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>Sonstiges</summary> <ol> <li><a href="/de/docs/Web/JavaScript/JavaScript_technologies_overview">JavaScript-Technologie (Übersicht)</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Lexical_grammar">Lexikalische Grammatik</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Iteration_protocols">Iterationsprotokolle</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Strict_mode">Strenger Modus</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Template_literals">Vorlagenliterale</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Trailing_commas">Abschließende Kommas</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features">Veraltete Funktionen</a></li> </ol> </details> </li> </ol> </div></div><section class="place side"></section></nav></aside><div class="toc-container"><aside class="toc"><nav><div class="document-toc-container"><section class="document-toc"><header><h2 class="document-toc-heading">In diesem Artikel</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#probieren_sie_es_aus">Probieren Sie es aus</a></li><li class="document-toc-item "><a class="document-toc-link" href="#syntax">Syntax</a></li><li class="document-toc-item "><a class="document-toc-link" href="#beschreibung">Beschreibung</a></li><li class="document-toc-item "><a class="document-toc-link" href="#beispiele">Beispiele</a></li><li class="document-toc-item "><a class="document-toc-link" href="#spezifikationen">Spezifikationen</a></li><li class="document-toc-item "><a class="document-toc-link" href="#browser-kompatibilität">Browser-Kompatibilität</a></li><li class="document-toc-item "><a class="document-toc-link" href="#siehe_auch">Siehe auch</a></li></ul></section></div></nav></aside><section class="place side"></section></div></div><main id="content" class="main-content "><article class="main-page-content" lang="de"><header><h1>for...in</h1><details class="baseline-indicator high"><summary><span class="indicator" role="img" aria-label="Baseline Check"></span><h2>Baseline <span class="not-bold">Widely available</span></h2><div class="browsers"><span class="engine" title="Supported in Chrome and Edge"><span class="browser chrome supported" role="img" aria-label="Chrome check"></span><span class="browser edge supported" role="img" aria-label="Edge check"></span></span><span class="engine" title="Supported in Firefox"><span class="browser firefox supported" role="img" aria-label="Firefox check"></span></span><span class="engine" title="Supported in Safari"><span class="browser safari supported" role="img" aria-label="Safari check"></span></span></div><span class="icon icon-chevron "></span></summary><div class="extra"><p>This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.</p><ul><li><a href="/de/docs/Glossary/Baseline/Compatibility" data-glean="baseline_link_learn_more" target="_blank" class="learn-more">Learn more</a></li><li><a href="#browser-kompatibilität" data-glean="baseline_link_bcd_table">See full compatibility</a></li><li><a href="https://survey.alchemer.com/s3/7634825/MDN-baseline-feedback?page=%2Fde%2Fdocs%2FWeb%2FJavaScript%2FReference%2FStatements%2Ffor...in&level=high" data-glean="baseline_link_feedback" class="feedback-link" target="_blank" rel="noreferrer">Report feedback</a></li></ul></div></details></header><div class="section-content"><p>Die <strong><code>for...in</code></strong>-Anweisung iteriert über alle <a href="/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties">enumerierbaren String-Eigenschaften</a> eines Objekts (ignoring properties keyed by <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Symbol">symbols</a>), einschließlich geerbter enumerierbarer Eigenschaften.</p></div><section aria-labelledby="probieren_sie_es_aus"><h2 id="probieren_sie_es_aus"><a href="#probieren_sie_es_aus">Probieren Sie es aus</a></h2><div class="section-content"><iframe class="interactive is-js-height" height="200" src="https://interactive-examples.mdn.mozilla.net/pages/js/statement-forin.html" title="MDN Web Docs Interactive Example" allow="clipboard-write" loading="lazy"></iframe></div></section><section aria-labelledby="syntax"><h2 id="syntax"><a href="#syntax">Syntax</a></h2><div class="section-content"><div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>for (variable in object) statement </code></pre></div></div></section><section aria-labelledby="parameter"><h3 id="parameter"><a href="#parameter">Parameter</a></h3><div class="section-content"><dl> <dt id="variable"><a href="#variable"><code>variable</code></a></dt> <dd> <p>Erhält bei jeder Iteration einen String-Eigenschaftsnamen. Kann entweder eine Deklaration mit <a href="/de/docs/Web/JavaScript/Reference/Statements/const"><code>const</code></a>, <a href="/de/docs/Web/JavaScript/Reference/Statements/let"><code>let</code></a> oder <a href="/de/docs/Web/JavaScript/Reference/Statements/var"><code>var</code></a> sein oder ein <a href="/de/docs/Web/JavaScript/Reference/Operators/Assignment">Zuweisungsziel</a> (z.B. eine zuvor deklarierte Variable, eine Objekteigenschaft oder ein <a href="/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment">Destrukturierungszuweisung-Muster</a>). Mit <code>var</code> deklarierte Variablen sind nicht lokal zur Schleife, d.h., sie befinden sich im selben Scope, in dem sich die <code>for...in</code>-Schleife befindet.</p> </dd> <dt id="object"><a href="#object"><code>object</code></a></dt> <dd> <p>Objekt, dessen nicht-symbolische enumerierbare Eigenschaften durchlaufen werden.</p> </dd> <dt id="statement"><a href="#statement"><code>statement</code></a></dt> <dd> <p>Eine Anweisung, die bei jeder Iteration ausgeführt wird. Kann auf <code>variable</code> verweisen. Sie können einen <a href="/de/docs/Web/JavaScript/Reference/Statements/block">Blocksatz</a> verwenden, um mehrere Anweisungen auszuführen.</p> </dd> </dl></div></section><section aria-labelledby="beschreibung"><h2 id="beschreibung"><a href="#beschreibung">Beschreibung</a></h2><div class="section-content"><p>Die Schleife iteriert über alle enumerierbaren Eigenschaften des Objekts selbst und über jene, die das Objekt von seiner Prototypen-Kette erbt (Eigenschaften näherer Prototypen haben Vorrang vor denen von Prototypen, die weiter vom Objekt in seiner Prototypen-Kette entfernt sind).</p> <p>Wie andere Schleifenanweisungen können Sie <a href="/de/docs/Web/JavaScript/Reference/Statements#control_flow">Steuerflussanweisungen</a> innerhalb von <code>statement</code> verwenden:</p> <ul> <li><a href="/de/docs/Web/JavaScript/Reference/Statements/break"><code>break</code></a> stoppt die Ausführung von <code>statement</code> und geht zur ersten Anweisung nach der Schleife.</li> <li><a href="/de/docs/Web/JavaScript/Reference/Statements/continue"><code>continue</code></a> stoppt die Ausführung von <code>statement</code> und geht zur nächsten Iteration der Schleife.</li> </ul> <p>Eine <code>for...in</code>-Schleife iteriert nur über enumerierbare, nicht-symbolische Eigenschaften. Von eingebauten Konstruktoren wie <code>Array</code> und <code>Object</code> erstellte Objekte haben geerbte nicht-enumerierbare Eigenschaften von <code>Array.prototype</code> und <code>Object.prototype</code>, wie die <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Array"><code>Array</code></a>-Methode <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf"><code>indexOf()</code></a> oder die <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object"><code>Object</code></a>-Methode <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/toString"><code>toString()</code></a>, die in der <code>for...in</code>-Schleife nicht besucht werden.</p> <p>Die Traversierungsreihenfolge ist laut moderner ECMAScript-Spezifikation gut definiert und konsistent über alle Implementierungen hinweg. Innerhalb jeder Komponente der Prototypenkette werden alle nicht-negativen ganzzahligen Schlüssel (die als Array-Indizes verwendet werden können) zuerst in aufsteigender Reihenfolge durchlaufen, dann andere String-Schlüssel in aufsteigender chronologischer Reihenfolge der Eigenschaftserstellung.</p> <p>Der <code>variable</code>-Teil von <code>for...in</code> akzeptiert alles, was vor dem <code>=</code>-Operator stehen kann. Sie können <a href="/de/docs/Web/JavaScript/Reference/Statements/const"><code>const</code></a> verwenden, um die Variable zu deklarieren, solange sie nicht innerhalb des Schleifenkörpers erneut zugewiesen wird (sie kann zwischen den Iterationen wechseln, da dies zwei separate Variablen sind). Andernfalls können Sie <a href="/de/docs/Web/JavaScript/Reference/Statements/let"><code>let</code></a> verwenden. Sie können <a href="/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment">Destrukturierung</a> verwenden, um mehrere lokale Variablen zuzuweisen, oder einen Eigenschafts-Accessor wie <code>for (x.y in iterable)</code> verwenden, um den Wert einer Objekteigenschaft zuzuweisen.</p> <p>Ein <a href="/de/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features#statements">veraltetes Syntax</a> erlaubt <code>var</code>-Deklarationen der Schleifenvariable mit einem Initialisierer. Dies führt zu einem <a href="/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer">Syntaxfehler</a> im strikten Modus und wird im nicht-strikten Modus ignoriert.</p></div></section><section aria-labelledby="gelöschte_hinzugefügte_oder_modifizierte_eigenschaften"><h3 id="gelöschte_hinzugefügte_oder_modifizierte_eigenschaften"><a href="#gelöschte_hinzugefügte_oder_modifizierte_eigenschaften">Gelöschte, hinzugefügte oder modifizierte Eigenschaften</a></h3><div class="section-content"><p><code>for...in</code> besucht Eigenschaftsschlüssel in folgender Weise:</p> <ol> <li>Es erhält zuerst alle eigenen String-Schlüssel des aktuellen Objekts, in einer Art, die der von <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames"><code>Object.getOwnPropertyNames()</code></a> sehr ähnlich ist.</li> <li>Für jeden Schlüssel, falls noch kein String mit dem gleichen Wert besucht wurde, wird der <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor">Eigenschaftsbeschreiber abgerufen</a> und die Eigenschaft wird nur besucht, wenn sie enumerierbar ist. Dieser Eigenschaftsstring wird jedoch als besucht markiert, selbst wenn er nicht enumerierbar ist.</li> <li>Dann wird das aktuelle Objekt durch seinen Prototyp ersetzt und der Prozess wird wiederholt.</li> </ol> <p>Dies bedeutet:</p> <ul> <li>Jede während der Iteration dem aktuell besuchten Objekt hinzugefügte Eigenschaft wird nicht besucht, da alle eigenen Eigenschaften des aktuellen Objekts bereits zuvor gespeichert wurden.</li> <li>Wenn mehrere Objekte in der Prototypenkette eine Eigenschaft mit demselben Namen haben, wird nur die erste berücksichtigt, und sie wird nur besucht, wenn sie enumerierbar ist. Wenn sie nicht enumerierbar ist, werden keine anderen Eigenschaften mit demselben Namen weiter oben in der Prototypenkette besucht, auch wenn sie enumerierbar sind.</li> </ul> <p>Im Allgemeinen ist es am besten, Eigenschaften des Objekts während der Iteration nicht hinzuzufügen, zu ändern oder zu entfernen, außer der aktuell besuchten Eigenschaft. Die Spezifikation erlaubt es ausdrücklich, dass die Implementierung nicht dem oben beschriebenen Algorithmus folgt, wenn einer der folgenden Fälle auftritt:</p> <ul> <li>Die Prototypenkette des Objekts wird während der Iteration verändert.</li> <li>Eine Eigenschaft wird während der Iteration vom Objekt oder seiner Prototypenkette gelöscht.</li> <li>Eine Eigenschaft wird während der Iteration zur Prototypenkette des Objekts hinzugefügt.</li> <li>Die Enumerierbarkeit einer Eigenschaft wird während der Iteration geändert.</li> </ul> <p>In diesen Fällen können Implementierungen anders verhalten als Sie vielleicht erwarten, oder sogar voneinander abweichen.</p></div></section><section aria-labelledby="array-iteration_und_for...in"><h3 id="array-iteration_und_for...in"><a href="#array-iteration_und_for...in">Array-Iteration und for...in</a></h3><div class="section-content"><p>Array-Indizes sind nur enumerierbare Eigenschaften mit ganzzahligen Namen und sind ansonsten identisch mit allgemeinen Objekteigenschaften. Die <code>for...in</code>-Schleife durchläuft alle ganzzahligen Schlüssel, bevor sie andere Schlüssel durchläuft, und in strikt aufsteigender Reihenfolge, was das Verhalten von <code>for...in</code> der normalen Array-Iteration nahe bringt. Die <code>for...in</code>-Schleife gibt jedoch alle enumerierbaren Eigenschaften zurück, einschließlich solcher mit nicht-ganzzahligen Namen und solchen, die geerbt sind. Im Gegensatz zu <code>for...of</code> verwendet <code>for...in</code> die Eigenschaften-Aufzählung anstelle des Iterators des Arrays. In <a href="/de/docs/Web/JavaScript/Guide/Indexed_collections#sparse_arrays">spärlichen Arrays</a> wird <code>for...of</code> die leeren Slots besuchen, aber <code>for...in</code> wird dies nicht tun.</p> <p>Es ist besser, eine <a href="/de/docs/Web/JavaScript/Reference/Statements/for"><code>for</code></a>-Schleife mit einem numerischen Index, <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach"><code>Array.prototype.forEach()</code></a> oder die <a href="/de/docs/Web/JavaScript/Reference/Statements/for...of"><code>for...of</code></a>-Schleife zu verwenden, da sie den Index als Zahl und nicht als String zurückgeben und auch nicht-Index-Eigenschaften vermeiden.</p></div></section><section aria-labelledby="nur_eigene_eigenschaften_iterieren"><h3 id="nur_eigene_eigenschaften_iterieren"><a href="#nur_eigene_eigenschaften_iterieren">Nur eigene Eigenschaften iterieren</a></h3><div class="section-content"><p>Wenn Sie nur die Eigenschaften betrachten möchten, die an das Objekt selbst angehängt sind, und nicht seine Prototypen, können Sie eine der folgenden Techniken verwenden:</p> <ul> <li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/keys"><code>Object.keys()</code></a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames"><code>Object.getOwnPropertyNames()</code></a></li> </ul> <p><code>Object.keys</code> wird eine Liste der eigenen enumerierbaren String-Eigenschaften zurückgeben, während <code>Object.getOwnPropertyNames</code> auch nicht-enumerierbare enthält.</p> <p>Viele JavaScript-Stilrichtlinien und -Linter raten von der Verwendung von <code>for...in</code> ab, da es über die gesamte Prototypenkette iteriert, was selten gewünscht ist, und möglicherweise eine Verwechslung mit der weiter verbreiteten <code>for...of</code>-Schleife besteht. <code>for...in</code> wird am praktischsten für Debugging-Zwecke verwendet, da es eine einfache Möglichkeit bietet, die Eigenschaften eines Objekts zu überprüfen (indem es auf die Konsole ausgegeben wird oder auf andere Weise). In Situationen, in denen Objekte als Ad-hoc-Schlüssel-Wert-Paare verwendet werden, ermöglicht <code>for...in</code> Ihnen, zu überprüfen, ob einer dieser Schlüssel einen bestimmten Wert hält.</p></div></section><section aria-labelledby="beispiele"><h2 id="beispiele"><a href="#beispiele">Beispiele</a></h2><div class="section-content"></div></section><section aria-labelledby="verwendung_von_for...in"><h3 id="verwendung_von_for...in"><a href="#verwendung_von_for...in">Verwendung von for...in</a></h3><div class="section-content"><p>Die <code>for...in</code>-Schleife unten iteriert über alle enumerierbaren, nicht-symbolische Eigenschaften des Objekts und protokolliert einen String der Eigenschaftsnamen und ihrer Werte.</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const obj = { a: 1, b: 2, c: 3 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); } // Logs: // "obj.a = 1" // "obj.b = 2" // "obj.c = 3" </code></pre></div></div></section><section aria-labelledby="eigene_eigenschaften_iterieren"><h3 id="eigene_eigenschaften_iterieren"><a href="#eigene_eigenschaften_iterieren">Eigene Eigenschaften iterieren</a></h3><div class="section-content"><p>Die folgende Funktion veranschaulicht die Verwendung von <a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn"><code>Object.hasOwn()</code></a>: die geerbten Eigenschaften werden nicht angezeigt.</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const triangle = { a: 1, b: 2, c: 3 }; function ColoredTriangle() { this.color = "red"; } ColoredTriangle.prototype = triangle; const obj = new ColoredTriangle(); for (const prop in obj) { if (Object.hasOwn(obj, prop)) { console.log(`obj.${prop} = ${obj[prop]}`); } } // Logs: // "obj.color = red" </code></pre></div></div></section><section aria-labelledby="gleichzeitige_modifikation"><h3 id="gleichzeitige_modifikation"><a href="#gleichzeitige_modifikation">Gleichzeitige Modifikation</a></h3><div class="section-content"><div class="notecard warning"> <p><strong>Warnung:</strong> Sie sollten keinen solchen Code selbst schreiben. Er ist hier nur enthalten, um das Verhalten von <code>for...in</code> in einigen Grenzfällen zu veranschaulichen.</p> </div> <p>Eigenschaften, die dem aktuellen Objekt während der Iteration hinzugefügt werden, werden niemals besucht:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const obj = { a: 1, b: 2 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); obj.c = 3; } // Logs: // obj.a = 1 // obj.b = 2 </code></pre></div> <p>Überschattete Eigenschaften werden nur einmal besucht:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const proto = { a: 1 }; const obj = { __proto__: proto, a: 2 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); } // Logs: // obj.a = 2 Object.defineProperty(obj, "a", { enumerable: false }); for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); } // Logs nothing, because the first "a" property visited is non-enumerable. </code></pre></div> <p>Zusätzlich beachten Sie folgende Fälle, in denen das Verhalten nicht spezifiziert ist und Implementierungen dazu neigen können, vom spezifizierten Algorithmus abzuweichen:</p> <p>Ändern des Prototyps während der Iteration:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const obj = { a: 1, b: 2 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); Object.setPrototypeOf(obj, { c: 3 }); } </code></pre></div> <p>Löschen einer Eigenschaft während der Iteration:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const obj = { a: 1, b: 2, c: 3 }; // Deleting a property before it is visited for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); delete obj.c; } const obj2 = { a: 1, b: 2, c: 3 }; // Deleting a property after it is visited for (const prop in obj2) { console.log(`obj2.${prop} = ${obj2[prop]}`); delete obj2.a; } </code></pre></div> <p>Enumerierbare Eigenschaften, die während der Iteration zur Prototypenkette hinzugefügt werden:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const proto = {}; const obj = { __proto__: proto, a: 1, b: 2 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); proto.c = 3; } </code></pre></div> <p>Ändern der Enumerierbarkeit einer Eigenschaft während der Iteration:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const obj = { a: 1, b: 2, c: 3 }; for (const prop in obj) { console.log(`obj.${prop} = ${obj[prop]}`); Object.defineProperty(obj, "c", { enumerable: false }); } </code></pre></div></div></section><h2 id="spezifikationen"><a href="#spezifikationen">Spezifikationen</a></h2><table class="standard-table"><thead><tr><th scope="col">Specification</th></tr></thead><tbody><tr><td><a href="https://tc39.es/ecma262/multipage/ecmascript-language-statements-and-declarations.html#sec-for-in-and-for-of-statements">ECMAScript Language Specification <br/><small># sec-for-in-and-for-of-statements</small></a></td></tr></tbody></table><h2 id="browser-kompatibilität"><a href="#browser-kompatibilität">Browser-Kompatibilität</a></h2><p>BCD tables only load in the browser<noscript> with JavaScript enabled. Enable JavaScript to view data.</noscript></p><section aria-labelledby="siehe_auch"><h2 id="siehe_auch"><a href="#siehe_auch">Siehe auch</a></h2><div class="section-content"><ul> <li><a href="/de/docs/Web/JavaScript/Reference/Statements/for...of"><code>for...of</code></a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Statements/for"><code>for</code></a></li> <li><a href="/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties">Enumerierbarkeit und Besitz von Eigenschaften</a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames"><code>Object.getOwnPropertyNames()</code></a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn"><code>Object.hasOwn()</code></a></li> <li><a href="/de/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach"><code>Array.prototype.forEach()</code></a></li> </ul></div></section></article><aside class="article-footer"><div class="article-footer-inner"><div 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href=\"/de/docs/Learn/Getting_started_with_the_web/JavaScript_basics\">JavaScript-Grundlagen</a></li>\n <li><a href=\"/de/docs/Learn/JavaScript/First_steps\">Erste Schritte in JavaScript</a></li>\n <li><a href=\"/de/docs/Learn/JavaScript/Building_blocks\">JavaScript-Bausteine</a></li>\n <li><a href=\"/de/docs/Learn/JavaScript/Objects\">Einführung in JavaScript-Objekte</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>JavaScript-Handbuch</summary>\n <ol>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Introduction\">Einführung</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Grammar_and_types\">Grammatik und Typen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Control_flow_and_error_handling\">Steuerfluss und Fehlerbehandlung</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Loops_and_iteration\">Schleifen und Iteration</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Functions\">Funktionen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Expressions_and_operators\">Ausdrücke und Operatoren</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Numbers_and_dates\">Zahlen und Daten</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Text_formatting\">Textformatierung</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Regular_expressions\">Reguläre Ausdrücke</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Indexed_collections\">Indexierte Sammlungen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Keyed_collections\">Gekennzeichnete Sammlungen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Working_with_objects\">Arbeiten mit Objekten</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Using_classes\">Verwendung von Klassen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Using_promises\">Verwendung von Promises</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Typed_arrays\">Typisierte Arrays in JavaScript</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Iterators_and_generators\">Iteratoren und Generatoren</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Meta_programming\">Metaprogrammierung</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Guide/Modules\">JavaScript-Module</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Mittelstufe</summary>\n <ol>\n <li><a href=\"/de/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks\">Client-seitige JavaScript-Frameworks</a></li>\n <li><a href=\"/de/docs/Learn/JavaScript/Client-side_web_APIs\">Client-seitige Web-APIs</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Language_overview\">Sprachübersicht</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Data_structures\">JavaScript-Datenstrukturen</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Equality_comparisons_and_sameness\">Gleichheitsvergleiche und Gleichheit</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties\">Aufzählbarkeit und Eigentum von Eigenschaften</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Closures\">Closures</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Fortgeschritten</summary>\n <ol>\n <li><a href=\"/de/docs/Web/JavaScript/Inheritance_and_the_prototype_chain\">Vererbung und die Prototypenkette</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Memory_management\">Speicherverwaltung</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Event_loop\">Konkurrenzmodell und Ereignisschleife</a></li>\n </ol>\n </details>\n </li>\n <li class=\"section\"><a href=\"/de/docs/Web/JavaScript/Reference\">Referenzen</a></li>\n <li class=\"toggle\">\n <details>\n <summary>Eingebaute Objekte</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects\">Standard eingebaute Objekte</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/AggregateError\">AggregateError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Array\">Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer\">ArrayBuffer</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncFunction\">AsyncFunction</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncGenerator\">AsyncGenerator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncGeneratorFunction\">AsyncGeneratorFunction</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/AsyncIterator\">AsyncIterator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Atomics\">Atomics</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/BigInt\">BigInt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/BigInt64Array\">BigInt64Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/BigUint64Array\">BigUint64Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Boolean\">Boolean</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/DataView\">DataView</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Date\">Date</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/decodeURI\">decodeURI()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent\">decodeURIComponent()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/encodeURI\">encodeURI()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent\">encodeURIComponent()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Error\">Error</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/escape\">escape()</a><abbr class=\"icon icon-deprecated\" title=\"Veraltet. Nicht für neue Websites verwenden.\">\n <span class=\"visually-hidden\">Veraltet</span>\n</abbr></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/eval\">eval()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/EvalError\">EvalError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry\">FinalizationRegistry</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Float16Array\">Float16Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Float32Array\">Float32Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Float64Array\">Float64Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Function\">Function</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Generator\">Generator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/GeneratorFunction\">GeneratorFunction</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/globalThis\">globalThis</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Infinity\">Infinity</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Int16Array\">Int16Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Int32Array\">Int32Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Int8Array\">Int8Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/InternalError\">InternalError</a><abbr class=\"icon icon-nonstandard\" title=\"Nicht standardisiert. Überprüfen Sie die Unterstützung in verschiedenen Browsern, bevor Sie es verwenden.\">\n <span class=\"visually-hidden\">Nicht standardisiert</span>\n</abbr></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Intl\">Intl</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/isFinite\">isFinite()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/isNaN\">isNaN()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Iterator\">Iterator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/JSON\">JSON</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Map\">Map</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Math\">Math</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/NaN\">NaN</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Number\">Number</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object\">Object</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/parseFloat\">parseFloat()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/parseInt\">parseInt()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Promise\">Promise</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Proxy\">Proxy</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/RangeError\">RangeError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError\">ReferenceError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Reflect\">Reflect</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/RegExp\">RegExp</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Set\">Set</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer\">SharedArrayBuffer</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/String\">String</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Symbol\">Symbol</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError\">SyntaxError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/TypedArray\">TypedArray</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/TypeError\">TypeError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array\">Uint16Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array\">Uint32Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array\">Uint8Array</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Uint8ClampedArray\">Uint8ClampedArray</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/undefined\">undefined</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/unescape\">unescape()</a><abbr class=\"icon icon-deprecated\" title=\"Veraltet. Nicht für neue Websites verwenden.\">\n <span class=\"visually-hidden\">Veraltet</span>\n</abbr></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/URIError\">URIError</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/WeakMap\">WeakMap</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/WeakRef\">WeakRef</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/WeakSet\">WeakSet</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Ausdrücke und Operatoren</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators\">Ausdrücke und Operatoren</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Addition\">Addition (+)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Addition_assignment\">Addition Assignment (+=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Assignment\">Zuweisung (=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/async_function\">async function expression</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/async_function*\">async function* Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/await\">await</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_AND\">Bitweises UND (&)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_AND_assignment\">Bitweise UND-Zuweisung (&=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT\">Bitweise NOT (~)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_OR\">Bitweises Oder (|)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_OR_assignment\">Bitweises OR-Zuweisung (|=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR\">Bitweises XOR (^)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR_assignment\">Bitweises XOR-Zuweisung (^=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/class\">Klassenausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Comma_operator\">Komma-Operator (,)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Conditional_operator\">Bedingungsoperator (ternärer Operator)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Decrement\">Decrement (--)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/delete\">delete</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment\">Destructuring-Zuweisung</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Division\">Division (/)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Division_assignment\">Division assignment (/=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Equality\">Gleichheit (==)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Exponentiation\">Potenzierung (**)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Exponentiation_assignment\">Exponentiation-Zuweisung (**=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/function\">function expression</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/function*\">function* Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Greater_than\">Greater than (>)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Greater_than_or_equal\">Greater than or equal (>=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Grouping\">Gruppierungsoperator ( )</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/import.meta\">import.meta</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/import\">import()</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/in\">in</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Increment\">Increment (++)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Inequality\">Inequality (!=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/instanceof\">instanceof</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Left_shift\">Left shift (<<)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Left_shift_assignment\">Left shift assignment (<<=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Less_than\">Less than (<)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Less_than_or_equal\">Less than or equal (<=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Logical_AND\">Logisches UND (&&)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment\">Logical AND assignment (&&=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Logical_NOT\">Logisches NICHT (!)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Logical_OR\">Logical OR (||)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment\">Logische ODER-Zuweisung (||=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Multiplication\">Multiplication (*)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Multiplication_assignment\">Multiplikationszuweisung (*=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/new\">new</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/new.target\">new.target</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/null\">null</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_assignment\">Nullish coalescing assignment (??=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing\">Nullish coalescing-Operator (??)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Object_initializer\">Object initializer</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Operator_precedence\">Operatorpriorität</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Optional_chaining\">Optional Chaining (?.)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Property_accessors\">Property accessors</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Remainder\">Remainder (%)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Remainder_assignment\">Remainder-Zuweisung (%=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Right_shift\">Rechtsschiebung (>>)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Right_shift_assignment\">Right shift assignment (>>=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Spread_syntax\">Spread-Syntax (...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Strict_equality\">Strikte Gleichheit (===)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Strict_inequality\">Strikte Ungleichheit (!==)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Subtraction\">Subtraction (-)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Subtraction_assignment\">Subtraction assignment (-=)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/super\">super</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/this\">this</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/typeof\">typeof</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Unary_negation\">Unäre Negation (-)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Unary_plus\">Unary plus (+)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift\">Unsigned right shift (>>>)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment\">Unsigned right shift assignment (`>>>=`)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/void\">void operator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/yield\">yield</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Operators/yield*\">yield*</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details open=\"\">\n <summary>Anweisungen und Deklarationen</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements\">Statements und Deklarationen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/async_function\">async function</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/async_function*\">async function*</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/block\">Block Statement</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/break\">break</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/class\">class</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/const\">const</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/continue\">continue</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/debugger\">debugger</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/do...while\">do...while</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/Empty\">Empty Statement</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/export\">export</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/Expression_statement\">Expression statement</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for\">for</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for-await...of\">for await...of</a></li><li><em><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for...in\" aria-current=\"page\">for...in</a></em></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for...of\">for...of</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/function\">function</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/function*\">function*</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/if...else\">if...else</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/import\">import</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/label\">Labelierte Anweisung</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/let\">let</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/return\">return</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/switch\">switch</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/throw\">throw</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/try...catch\">try...catch</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/var\">var</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/while\">while</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/with\">with</a><abbr class=\"icon icon-deprecated\" title=\"Veraltet. Nicht für neue Websites verwenden.\">\n <span class=\"visually-hidden\">Veraltet</span>\n</abbr></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Funktionen</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions\">Functions</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/Arrow_functions\">Pfeilfunktionen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/Default_parameters\">Default parameters</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/get\">get</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/Method_definitions\">Methodendefinitionen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/rest_parameters\">Rest-Parameter</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/set\">set</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Functions/arguments\">Das arguments Objekt</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Klassen</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes\">Klassen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/constructor\">constructor</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/extends\">extends</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/Private_properties\">Private properties</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/Public_class_fields\">Public class fields</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/static\">static</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks\">Statische Initialisierungsblöcke</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Reguläre Ausdrücke</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions\">Regular expressions</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Backreference\">Backreference: \\1, \\2</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Capturing_group\">Capturing group: (...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape\">Zeichenklassen-Escape: \\d, \\D, \\w, \\W, \\s, \\S</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_class\">Zeichenklasse: [...], [^...]</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape\">Zeichen-Escape: \\n, \\u{...}</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Disjunction\">Disjunktion: |</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Input_boundary_assertion\">Input-Bereichs-Assertion: ^, $</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Literal_character\">Literalzeichen: a, b</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Lookahead_assertion\">Lookahead-Assertion: (?=...), (?!...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Lookbehind_assertion\">Lookbehind Assertion: (?<=...), (?<!...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Modifier\">Modifikator: (?ims-ims:...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Named_backreference\">Benannte Rückreferenz: \\k<name></a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Named_capturing_group\">Named capturing group: (?<name>...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Non-capturing_group\">Nicht erfassende Gruppe: (?:...)</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Quantifier\">Quantifier: *, +, ?, {n}, {n,}, {n,m}</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape\">Unicode-Zeichenklassenescapes: \\p{...}, \\P{...}</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Wildcard\">Wildcard: .</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Regular_expressions/Word_boundary_assertion\">Wortgrenzen-Assertion: \\b, \\B</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Fehler</summary>\n <ol><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors\">JavaScript-Fehlerreferenz</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Promise_any_all_rejected\">AggregateError: Kein Promise in Promise.any wurde aufgelöst</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Property_access_denied\">Fehler: Zugriff verweigert auf Eigenschaft \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Too_much_recursion\">InternalError: zu viel Rekursion</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Not_a_valid_code_point\">RangeError: argument ist kein gültiger Codepunkt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/BigInt_division_by_zero\">RangeError: BigInt-Division durch Null</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/BigInt_negative_exponent\">RangeError: BigInt negative exponent</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Form_must_be_one_of\">RangeError: form muss einer von 'NFC', 'NFD', 'NFKC' oder 'NFKD' sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_array_length\">RangeError: invalid array length</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_date\">RangeError: invalid date</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Precision_range\">RangeError: precision liegt außerhalb des zulässigen Bereichs</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_radix\">RangeError: radix muss eine ganze Zahl sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Resulting_string_too_large\">RangeError: repeat count muss kleiner als unendlich sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Negative_repetition_count\">RangeError: repeat count must be non-negative</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_be_converted_to_BigInt_because_it_isnt_an_integer\">RangeError: x kann nicht in BigInt konvertiert werden, da es keine ganze Zahl ist</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Not_defined\">ReferenceError: \"x\" ist nicht definiert</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Undeclared_var\">ReferenceError: Zuordnung zu einer nicht deklarierten Variable \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_access_lexical_declaration_before_init\">ReferenceError: kann auf lexikalische Deklaration 'X' vor der Initialisierung nicht zugreifen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Deprecated_caller_or_arguments_usage\">ReferenceError: veraltete Verwendung von caller oder arguments</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Super_not_called\">ReferenceError: 'super' Konstruktor muss vor der Verwendung von 'this' im Konstruktor der abgeleiteten Klasse aufgerufen werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Super_called_twice\">ReferenceError: super() zweimal im abgeleiteten Klassenkonstruktor aufgerufen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_strict_arguments_eval\">SyntaxError: 'arguments'/'eval' können im Strict-Mode-Code nicht definiert oder zugewiesen werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_literal\">SyntaxError: \"0\"-präfixierte Oktalliterale sind veraltet</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Strict_non_simple_params\">SyntaxError: \"use strict\" nicht erlaubt in Funktion mit nicht einfachen Parametern</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Reserved_identifier\">SyntaxError: \"x\" ist ein reservierter Bezeichner</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_backslash_at_end_of_pattern\">SyntaxError: \\ am Ende des Musters</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-of_initializer\">SyntaxError: Eine Deklaration im Kopf einer for-of-Schleife darf keinen Initialisierer haben</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Delete_in_strict_mode\">SyntaxError: Die Anwendung des 'delete'-Operators auf einen unqualifizierten Namen ist veraltet</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Arguments_not_allowed\">SyntaxError: arguments ist in Feldern nicht gültig</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_await\">SyntaxError: await ist nur in async Funktionen, async Generatoren und Modulen gültig</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/await_yield_in_parameter\">SyntaxError: await/yield expression kann nicht im Parameter verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_use_nullish_coalescing_unparenthesized\">SyntaxError: `??` kann nicht ohne Klammern innerhalb von `||` und `&&`-Ausdrücken verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_character_class_escape_in_class_range\">SyntaxError: Zeichenklassen-Escape kann nicht im Klassenbereich im regulären Ausdruck verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_continue\">SyntaxError: continue muss innerhalb einer Schleife sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_duplicate_capture_group_name\">SyntaxError: doppelter Name der Erfassungsgruppe im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Duplicate_parameter\">SyntaxError: doppeltes formales Argument x</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer\">SyntaxError: Deklarationen im Kopf einer for-in-Schleife dürfen keine Initialisierer enthalten</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Unnamed_function_statement\">SyntaxError: Funktionsanweisung erfordert einen Namen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Function_label\">SyntaxError: Funktionen können nicht beschriftet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Either_be_both_static_or_non-static\">SyntaxError: Getter und Setter für privaten Namen #x sollten entweder beide statisch oder nicht statisch sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Getter_no_arguments\">SyntaxError: Getter-Funktionen dürfen keine Argumente haben</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Identifier_after_number\">SyntaxError: identifier startet direkt nach einer numerischen Literal</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Illegal_character\">SyntaxError: illegales Zeichen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/import_decl_module_top_level\">SyntaxError: import-Deklarationen dürfen nur auf der obersten Ebene eines Moduls erscheinen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_incomplete_quantifier\">SyntaxError: unvollständiger Quantifizierer im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_assignment_left-hand_side\">SyntaxError: invalid assignment left-hand side</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_BigInt_syntax\">SyntaxError: Ungültige BigInt-Syntax</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_capture_group_name\">SyntaxError: ungültiger Name der Erfassungsgruppe im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_char_in_class\">SyntaxError: ungültiges Zeichen in Klasse in regulärem Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_class_set_operation\">SyntaxError: Ungültige Klassenmengenoperation im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_decimal_escape\">SyntaxError: ungültiger Dezimal-Escape in regulärem Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_identity_escape\">SyntaxError: ungültige Identitätsflucht in regulärem Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_named_capture_reference\">SyntaxError: ungültige benannte Referenz in regulärem Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_property_name\">SyntaxError: ungültiger Eigenschaftsname im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_range_in_character_class\">SyntaxError: invalid range in character class</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_group\">SyntaxError: invalid regexp group</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_regexp_flag\">SyntaxError: invalid regular expression flag \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_invalid_unicode_escape\">SyntaxError: ungültiger Unicode-Escape in regulärem Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/JSON_bad_parse\">SyntaxError: JSON.parse: Fehlerhaftes Parsing</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Label_not_found\">SyntaxError: label not found</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_colon_after_property_id\">SyntaxError: missing : after property id</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_argument_list\">SyntaxError: missing ) after argument list</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_condition\">SyntaxError: missing ) after condition</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_bracket_after_list\">SyntaxError: missing ] after element list</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_function_body\">SyntaxError: fehlende } nach Funktionskörper</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_property_list\">SyntaxError: missing } after property list</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_initializer_in_const\">SyntaxError: missing = in const declaration</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_formal_parameter\">SyntaxError: missing formal parameter</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Missing_name_after_dot_operator\">SyntaxError: missing name after . operator</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/No_variable_name\">SyntaxError: missing variable name</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_negated_char_class_with_strings\">SyntaxError: Negierte Zeichenklasse mit Strings im regulären Ausdruck</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_new_optional\">SyntaxError: new-Schlüsselwort kann nicht mit einer Optionalen Kette verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_nothing_to_repeat\">SyntaxError: nothing to repeat</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_numbers_out_of_order_in_quantifier\">SyntaxError: numbers out of order in {} quantifier.</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_escape_sequence\">SyntaxError: Oktale Escape-Sequenzen können nicht in nicht-getaggten Vorlagenliteralen oder im Strict Mode-Code verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Parameter_after_rest_parameter\">SyntaxError: parameter nach Rest-Parameter</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_delete_private_fields\">SyntaxError: private fields können nicht gelöscht werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Duplicate_proto\">SyntaxError: Eigenschaftenname __proto__ erscheint mehr als einmal im Objektliteral</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Regex_raw_bracket\">SyntaxError: Raw-Klammern sind im regulären Ausdruck mit Unicode-Flag nicht erlaubt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Redeclared_parameter\">SyntaxError: redeclaration of formal parameter \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Undeclared_private_field_or_method\">SyntaxError: Verweis auf nicht deklariertes privates Feld oder Methode #x</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Rest_with_default\">SyntaxError: Restparameter darf keinen Standardwert haben</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_return\">SyntaxError: return not in function</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Setter_one_argument\">SyntaxError: Setter-Funktionen müssen ein Argument haben</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/String_literal_EOL\">SyntaxError: string literal enthält einen nicht-escaped Zeilenumbruch</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_super_call\">SyntaxError: super() ist nur in Konstruktoren abgeleiteter Klassen gültig</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_optional_template\">SyntaxError: getaggtes Template kann nicht mit optionaler Verkettung verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Hash_outside_class\">SyntaxError: Unerwartetes '#' außerhalb des Klassenkörpers verwendet</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Unexpected_token\">SyntaxError: Unerwartetes Token</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_break\">SyntaxError: unlabeled break muss innerhalb einer Schleife oder eines Switch sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Unparenthesized_unary_expr_lhs_exponentiation\">SyntaxError: unverklammerter unärer Ausdruck kann nicht auf der linken Seite von '**' erscheinen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Bad_super_prop\">SyntaxError: Verwendung von Super-Eigenschaften/-mitgliedern ist nur innerhalb von Methoden oder eval-Code innerhalb von Methoden gültig</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Deprecated_source_map_pragma\">SyntaxError: Die Verwendung von //@ zur Angabe von sourceURL-Pragmas ist veraltet. Verwenden Sie stattdessen //#</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/is_not_iterable\">TypeError: 'x' ist nicht iterierbar</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Unexpected_type\">TypeError: \"x\" ist (nicht) \"y\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Not_a_constructor\">TypeError: \"x\" ist kein Konstruktor</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Not_a_function\">TypeError: \"x\" ist keine Funktion</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/No_non-null_object\">TypeError: \"x\" ist kein nicht-null-Objekt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Read-only\">TypeError: \"x\" ist schreibgeschützt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/BigInt_not_serializable\">TypeError: BigInt-Wert kann nicht in JSON serialisiert werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Builtin_ctor_no_new\">TypeError: Der Aufruf eines eingebauten X-Konstruktors ohne new ist verboten</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Get_set_missing_private\">TypeError: kann nicht auf privates Feld oder Methode zugreifen/setzen: Objekt ist nicht die richtige Klasse</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_assign_to_property\">TypeError: kann Eigenschaft „x“ auf „y“ nicht zuweisen: kein Objekt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_convert_BigInt_to_number\">TypeError: can't convert BigInt to number</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_convert_x_to_BigInt\">TypeError: kann x nicht in BigInt konvertieren</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_define_property_object_not_extensible\">TypeError: kann Eigenschaft \"x\" nicht definieren: \"obj\" ist nicht erweiterbar</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Non_configurable_array_element\">TypeError: can't delete non-configurable array element</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_redefine_property\">TypeError: kann nicht konfigurierbare Eigenschaft \"x\" neu definieren</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_set_prototype\">TypeError: kann das Prototyp dieses Objekts nicht festlegen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cyclic_prototype\">TypeError: can't set prototype: it would cause a prototype chain cycle</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/in_operator_no_object\">TypeError: kann den 'in'-Operator nicht verwenden, um nach 'x' in 'y' zu suchen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Class_ctor_no_new\">TypeError: Klassenkonstruktoren müssen mit 'new' aufgerufen werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value\">TypeError: cyclic object value</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_derived_return\">TypeError: abgeleiteter Klassenkonstruktor hat einen ungültigen Wert x zurückgegeben</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Private_setter_only\">TypeError: getting private setter-only property</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Private_double_initialization\">TypeError: Initialisierung eines Objekts zweimal ist ein Fehler bei privaten Feldern/Methoden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/invalid_right_hand_side_instanceof_operand\">TypeError: ungültiger 'instanceof'-Operand 'x'</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Array_sort_argument\">TypeError: invalides Array.prototype.sort Argument</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_const_assignment\">TypeError: ungültige Zuweisung zu const \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Constructor_cant_be_used_directly\">TypeError: Iterator/AsyncIterator-Konstruktor kann nicht direkt verwendet werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Requires_global_RegExp\">TypeError: matchAll/replaceAll muss mit einem globalen RegExp aufgerufen werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/More_arguments_needed\">TypeError: Mehr Argumente benötigt</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/No_properties\">TypeError: null/undefined hat keine Eigenschaften</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Cant_delete\">TypeError: Eigenschaft \"x\" ist nicht konfigurierbar und kann nicht gelöscht werden</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Reduce_of_empty_array_with_no_initial_value\">TypeError: Reduce eines leeren Arrays ohne initialen Wert</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Getter_only\">TypeError: Einstellung der nur-Getter-Eigenschaft \"x\"</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Key_not_weakly_held\">TypeError: WeakSet-Schlüssel/WeakMap-Wert 'x' muss ein Objekt oder ein nicht registriertes Symbol sein</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Called_on_incompatible_type\">TypeError: X.prototype.y auf inkompatiblen Typ aufgerufen</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Malformed_URI\">URIError: malformed URI sequence</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Already_has_pragma\">Warnung: -file- wird ein //# sourceMappingURL zugewiesen, hat aber bereits eines</a></li><li><a href=\"/de/docs/Web/JavaScript/Reference/Errors/Stmt_after_return\">Warnung: unerreichbarer Code nach return-Anweisung</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>Sonstiges</summary>\n <ol>\n <li><a href=\"/de/docs/Web/JavaScript/JavaScript_technologies_overview\">JavaScript-Technologie (Übersicht)</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Lexical_grammar\">Lexikalische Grammatik</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Iteration_protocols\">Iterationsprotokolle</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Strict_mode\">Strenger Modus</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Template_literals\">Vorlagenliterale</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Trailing_commas\">Abschließende Kommas</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features\">Veraltete Funktionen</a></li>\n </ol>\n </details>\n </li>\n </ol>\n","sidebarMacro":"JsSidebar","body":[{"type":"prose","value":{"id":null,"title":null,"isH3":false,"content":"<p>Die <strong><code>for...in</code></strong>-Anweisung iteriert über alle <a href=\"/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties\">enumerierbaren String-Eigenschaften</a> eines Objekts (ignoring properties keyed by <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Symbol\">symbols</a>), einschließlich geerbter enumerierbarer Eigenschaften.</p>"}},{"type":"prose","value":{"id":"probieren_sie_es_aus","title":"Probieren Sie es aus","isH3":false,"content":"<iframe class=\"interactive is-js-height\" height=\"200\" src=\"https://interactive-examples.mdn.mozilla.net/pages/js/statement-forin.html\" title=\"MDN Web Docs Interactive Example\" allow=\"clipboard-write\" loading=\"lazy\"></iframe>"}},{"type":"prose","value":{"id":"syntax","title":"Syntax","isH3":false,"content":"<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>for (variable in object)\n statement\n</code></pre></div>"}},{"type":"prose","value":{"id":"parameter","title":"Parameter","isH3":true,"content":"<dl>\n <dt id=\"variable\"><a href=\"#variable\"><code>variable</code></a></dt>\n <dd>\n <p>Erhält bei jeder Iteration einen String-Eigenschaftsnamen. Kann entweder eine Deklaration mit <a href=\"/de/docs/Web/JavaScript/Reference/Statements/const\"><code>const</code></a>, <a href=\"/de/docs/Web/JavaScript/Reference/Statements/let\"><code>let</code></a> oder <a href=\"/de/docs/Web/JavaScript/Reference/Statements/var\"><code>var</code></a> sein oder ein <a href=\"/de/docs/Web/JavaScript/Reference/Operators/Assignment\">Zuweisungsziel</a> (z.B. eine zuvor deklarierte Variable, eine Objekteigenschaft oder ein <a href=\"/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment\">Destrukturierungszuweisung-Muster</a>). Mit <code>var</code> deklarierte Variablen sind nicht lokal zur Schleife, d.h., sie befinden sich im selben Scope, in dem sich die <code>for...in</code>-Schleife befindet.</p>\n </dd>\n <dt id=\"object\"><a href=\"#object\"><code>object</code></a></dt>\n <dd>\n <p>Objekt, dessen nicht-symbolische enumerierbare Eigenschaften durchlaufen werden.</p>\n </dd>\n <dt id=\"statement\"><a href=\"#statement\"><code>statement</code></a></dt>\n <dd>\n <p>Eine Anweisung, die bei jeder Iteration ausgeführt wird. Kann auf <code>variable</code> verweisen. Sie können einen <a href=\"/de/docs/Web/JavaScript/Reference/Statements/block\">Blocksatz</a> verwenden, um mehrere Anweisungen auszuführen.</p>\n </dd>\n</dl>"}},{"type":"prose","value":{"id":"beschreibung","title":"Beschreibung","isH3":false,"content":"<p>Die Schleife iteriert über alle enumerierbaren Eigenschaften des Objekts selbst und über jene, die das Objekt von seiner Prototypen-Kette erbt (Eigenschaften näherer Prototypen haben Vorrang vor denen von Prototypen, die weiter vom Objekt in seiner Prototypen-Kette entfernt sind).</p>\n<p>Wie andere Schleifenanweisungen können Sie <a href=\"/de/docs/Web/JavaScript/Reference/Statements#control_flow\">Steuerflussanweisungen</a> innerhalb von <code>statement</code> verwenden:</p>\n<ul>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/break\"><code>break</code></a> stoppt die Ausführung von <code>statement</code> und geht zur ersten Anweisung nach der Schleife.</li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/continue\"><code>continue</code></a> stoppt die Ausführung von <code>statement</code> und geht zur nächsten Iteration der Schleife.</li>\n</ul>\n<p>Eine <code>for...in</code>-Schleife iteriert nur über enumerierbare, nicht-symbolische Eigenschaften. Von eingebauten Konstruktoren wie <code>Array</code> und <code>Object</code> erstellte Objekte haben geerbte nicht-enumerierbare Eigenschaften von <code>Array.prototype</code> und <code>Object.prototype</code>, wie die <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Array\"><code>Array</code></a>-Methode <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf\"><code>indexOf()</code></a> oder die <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object\"><code>Object</code></a>-Methode <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/toString\"><code>toString()</code></a>, die in der <code>for...in</code>-Schleife nicht besucht werden.</p>\n<p>Die Traversierungsreihenfolge ist laut moderner ECMAScript-Spezifikation gut definiert und konsistent über alle Implementierungen hinweg. Innerhalb jeder Komponente der Prototypenkette werden alle nicht-negativen ganzzahligen Schlüssel (die als Array-Indizes verwendet werden können) zuerst in aufsteigender Reihenfolge durchlaufen, dann andere String-Schlüssel in aufsteigender chronologischer Reihenfolge der Eigenschaftserstellung.</p>\n<p>Der <code>variable</code>-Teil von <code>for...in</code> akzeptiert alles, was vor dem <code>=</code>-Operator stehen kann. Sie können <a href=\"/de/docs/Web/JavaScript/Reference/Statements/const\"><code>const</code></a> verwenden, um die Variable zu deklarieren, solange sie nicht innerhalb des Schleifenkörpers erneut zugewiesen wird (sie kann zwischen den Iterationen wechseln, da dies zwei separate Variablen sind). Andernfalls können Sie <a href=\"/de/docs/Web/JavaScript/Reference/Statements/let\"><code>let</code></a> verwenden. Sie können <a href=\"/de/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment\">Destrukturierung</a> verwenden, um mehrere lokale Variablen zuzuweisen, oder einen Eigenschafts-Accessor wie <code>for (x.y in iterable)</code> verwenden, um den Wert einer Objekteigenschaft zuzuweisen.</p>\n<p>Ein <a href=\"/de/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features#statements\">veraltetes Syntax</a> erlaubt <code>var</code>-Deklarationen der Schleifenvariable mit einem Initialisierer. Dies führt zu einem <a href=\"/de/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer\">Syntaxfehler</a> im strikten Modus und wird im nicht-strikten Modus ignoriert.</p>"}},{"type":"prose","value":{"id":"gelöschte_hinzugefügte_oder_modifizierte_eigenschaften","title":"Gelöschte, hinzugefügte oder modifizierte Eigenschaften","isH3":true,"content":"<p><code>for...in</code> besucht Eigenschaftsschlüssel in folgender Weise:</p>\n<ol>\n <li>Es erhält zuerst alle eigenen String-Schlüssel des aktuellen Objekts, in einer Art, die der von <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames\"><code>Object.getOwnPropertyNames()</code></a> sehr ähnlich ist.</li>\n <li>Für jeden Schlüssel, falls noch kein String mit dem gleichen Wert besucht wurde, wird der <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor\">Eigenschaftsbeschreiber abgerufen</a> und die Eigenschaft wird nur besucht, wenn sie enumerierbar ist. Dieser Eigenschaftsstring wird jedoch als besucht markiert, selbst wenn er nicht enumerierbar ist.</li>\n <li>Dann wird das aktuelle Objekt durch seinen Prototyp ersetzt und der Prozess wird wiederholt.</li>\n</ol>\n<p>Dies bedeutet:</p>\n<ul>\n <li>Jede während der Iteration dem aktuell besuchten Objekt hinzugefügte Eigenschaft wird nicht besucht, da alle eigenen Eigenschaften des aktuellen Objekts bereits zuvor gespeichert wurden.</li>\n <li>Wenn mehrere Objekte in der Prototypenkette eine Eigenschaft mit demselben Namen haben, wird nur die erste berücksichtigt, und sie wird nur besucht, wenn sie enumerierbar ist. Wenn sie nicht enumerierbar ist, werden keine anderen Eigenschaften mit demselben Namen weiter oben in der Prototypenkette besucht, auch wenn sie enumerierbar sind.</li>\n</ul>\n<p>Im Allgemeinen ist es am besten, Eigenschaften des Objekts während der Iteration nicht hinzuzufügen, zu ändern oder zu entfernen, außer der aktuell besuchten Eigenschaft. Die Spezifikation erlaubt es ausdrücklich, dass die Implementierung nicht dem oben beschriebenen Algorithmus folgt, wenn einer der folgenden Fälle auftritt:</p>\n<ul>\n <li>Die Prototypenkette des Objekts wird während der Iteration verändert.</li>\n <li>Eine Eigenschaft wird während der Iteration vom Objekt oder seiner Prototypenkette gelöscht.</li>\n <li>Eine Eigenschaft wird während der Iteration zur Prototypenkette des Objekts hinzugefügt.</li>\n <li>Die Enumerierbarkeit einer Eigenschaft wird während der Iteration geändert.</li>\n</ul>\n<p>In diesen Fällen können Implementierungen anders verhalten als Sie vielleicht erwarten, oder sogar voneinander abweichen.</p>"}},{"type":"prose","value":{"id":"array-iteration_und_for...in","title":"Array-Iteration und for...in","isH3":true,"content":"<p>Array-Indizes sind nur enumerierbare Eigenschaften mit ganzzahligen Namen und sind ansonsten identisch mit allgemeinen Objekteigenschaften. Die <code>for...in</code>-Schleife durchläuft alle ganzzahligen Schlüssel, bevor sie andere Schlüssel durchläuft, und in strikt aufsteigender Reihenfolge, was das Verhalten von <code>for...in</code> der normalen Array-Iteration nahe bringt. Die <code>for...in</code>-Schleife gibt jedoch alle enumerierbaren Eigenschaften zurück, einschließlich solcher mit nicht-ganzzahligen Namen und solchen, die geerbt sind. Im Gegensatz zu <code>for...of</code> verwendet <code>for...in</code> die Eigenschaften-Aufzählung anstelle des Iterators des Arrays. In <a href=\"/de/docs/Web/JavaScript/Guide/Indexed_collections#sparse_arrays\">spärlichen Arrays</a> wird <code>for...of</code> die leeren Slots besuchen, aber <code>for...in</code> wird dies nicht tun.</p>\n<p>Es ist besser, eine <a href=\"/de/docs/Web/JavaScript/Reference/Statements/for\"><code>for</code></a>-Schleife mit einem numerischen Index, <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach\"><code>Array.prototype.forEach()</code></a> oder die <a href=\"/de/docs/Web/JavaScript/Reference/Statements/for...of\"><code>for...of</code></a>-Schleife zu verwenden, da sie den Index als Zahl und nicht als String zurückgeben und auch nicht-Index-Eigenschaften vermeiden.</p>"}},{"type":"prose","value":{"id":"nur_eigene_eigenschaften_iterieren","title":"Nur eigene Eigenschaften iterieren","isH3":true,"content":"<p>Wenn Sie nur die Eigenschaften betrachten möchten, die an das Objekt selbst angehängt sind, und nicht seine Prototypen, können Sie eine der folgenden Techniken verwenden:</p>\n<ul>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/keys\"><code>Object.keys()</code></a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames\"><code>Object.getOwnPropertyNames()</code></a></li>\n</ul>\n<p><code>Object.keys</code> wird eine Liste der eigenen enumerierbaren String-Eigenschaften zurückgeben, während <code>Object.getOwnPropertyNames</code> auch nicht-enumerierbare enthält.</p>\n<p>Viele JavaScript-Stilrichtlinien und -Linter raten von der Verwendung von <code>for...in</code> ab, da es über die gesamte Prototypenkette iteriert, was selten gewünscht ist, und möglicherweise eine Verwechslung mit der weiter verbreiteten <code>for...of</code>-Schleife besteht. <code>for...in</code> wird am praktischsten für Debugging-Zwecke verwendet, da es eine einfache Möglichkeit bietet, die Eigenschaften eines Objekts zu überprüfen (indem es auf die Konsole ausgegeben wird oder auf andere Weise). In Situationen, in denen Objekte als Ad-hoc-Schlüssel-Wert-Paare verwendet werden, ermöglicht <code>for...in</code> Ihnen, zu überprüfen, ob einer dieser Schlüssel einen bestimmten Wert hält.</p>"}},{"type":"prose","value":{"id":"beispiele","title":"Beispiele","isH3":false,"content":""}},{"type":"prose","value":{"id":"verwendung_von_for...in","title":"Verwendung von for...in","isH3":true,"content":"<p>Die <code>for...in</code>-Schleife unten iteriert über alle enumerierbaren, nicht-symbolische Eigenschaften des Objekts und protokolliert einen String der Eigenschaftsnamen und ihrer Werte.</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const obj = { a: 1, b: 2, c: 3 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n}\n\n// Logs:\n// \"obj.a = 1\"\n// \"obj.b = 2\"\n// \"obj.c = 3\"\n</code></pre></div>"}},{"type":"prose","value":{"id":"eigene_eigenschaften_iterieren","title":"Eigene Eigenschaften iterieren","isH3":true,"content":"<p>Die folgende Funktion veranschaulicht die Verwendung von <a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn\"><code>Object.hasOwn()</code></a>: die geerbten Eigenschaften werden nicht angezeigt.</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const triangle = { a: 1, b: 2, c: 3 };\n\nfunction ColoredTriangle() {\n this.color = \"red\";\n}\n\nColoredTriangle.prototype = triangle;\n\nconst obj = new ColoredTriangle();\n\nfor (const prop in obj) {\n if (Object.hasOwn(obj, prop)) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n }\n}\n\n// Logs:\n// \"obj.color = red\"\n</code></pre></div>"}},{"type":"prose","value":{"id":"gleichzeitige_modifikation","title":"Gleichzeitige Modifikation","isH3":true,"content":"<div class=\"notecard warning\">\n <p><strong>Warnung:</strong> Sie sollten keinen solchen Code selbst schreiben. Er ist hier nur enthalten, um das Verhalten von <code>for...in</code> in einigen Grenzfällen zu veranschaulichen.</p>\n</div>\n<p>Eigenschaften, die dem aktuellen Objekt während der Iteration hinzugefügt werden, werden niemals besucht:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const obj = { a: 1, b: 2 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n obj.c = 3;\n}\n\n// Logs:\n// obj.a = 1\n// obj.b = 2\n</code></pre></div>\n<p>Überschattete Eigenschaften werden nur einmal besucht:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const proto = { a: 1 };\nconst obj = { __proto__: proto, a: 2 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n}\n\n// Logs:\n// obj.a = 2\n\nObject.defineProperty(obj, \"a\", { enumerable: false });\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n}\n// Logs nothing, because the first \"a\" property visited is non-enumerable.\n</code></pre></div>\n<p>Zusätzlich beachten Sie folgende Fälle, in denen das Verhalten nicht spezifiziert ist und Implementierungen dazu neigen können, vom spezifizierten Algorithmus abzuweichen:</p>\n<p>Ändern des Prototyps während der Iteration:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const obj = { a: 1, b: 2 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n Object.setPrototypeOf(obj, { c: 3 });\n}\n</code></pre></div>\n<p>Löschen einer Eigenschaft während der Iteration:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const obj = { a: 1, b: 2, c: 3 };\n\n// Deleting a property before it is visited\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n delete obj.c;\n}\n\nconst obj2 = { a: 1, b: 2, c: 3 };\n\n// Deleting a property after it is visited\nfor (const prop in obj2) {\n console.log(`obj2.${prop} = ${obj2[prop]}`);\n delete obj2.a;\n}\n</code></pre></div>\n<p>Enumerierbare Eigenschaften, die während der Iteration zur Prototypenkette hinzugefügt werden:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const proto = {};\nconst obj = { __proto__: proto, a: 1, b: 2 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n proto.c = 3;\n}\n</code></pre></div>\n<p>Ändern der Enumerierbarkeit einer Eigenschaft während der Iteration:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const obj = { a: 1, b: 2, c: 3 };\n\nfor (const prop in obj) {\n console.log(`obj.${prop} = ${obj[prop]}`);\n Object.defineProperty(obj, \"c\", { enumerable: false });\n}\n</code></pre></div>"}},{"type":"specifications","value":{"title":"Spezifikationen","id":"spezifikationen","isH3":false,"specifications":[{"bcdSpecificationURL":"https://tc39.es/ecma262/multipage/ecmascript-language-statements-and-declarations.html#sec-for-in-and-for-of-statements","title":"ECMAScript Language Specification"}],"query":"javascript.statements.for_in"}},{"type":"browser_compatibility","value":{"title":"Browser-Kompatibilität","id":"browser-kompatibilität","isH3":false,"query":"javascript.statements.for_in"}},{"type":"prose","value":{"id":"siehe_auch","title":"Siehe auch","isH3":false,"content":"<ul>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for...of\"><code>for...of</code></a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Statements/for\"><code>for</code></a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Enumerability_and_ownership_of_properties\">Enumerierbarkeit und Besitz von Eigenschaften</a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames\"><code>Object.getOwnPropertyNames()</code></a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn\"><code>Object.hasOwn()</code></a></li>\n <li><a href=\"/de/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach\"><code>Array.prototype.forEach()</code></a></li>\n</ul>"}}],"toc":[{"text":"Probieren Sie es aus","id":"probieren_sie_es_aus"},{"text":"Syntax","id":"syntax"},{"text":"Beschreibung","id":"beschreibung"},{"text":"Beispiele","id":"beispiele"},{"text":"Spezifikationen","id":"spezifikationen"},{"text":"Browser-Kompatibilität","id":"browser-kompatibilität"},{"text":"Siehe auch","id":"siehe_auch"}],"summary":"Die for...in-Anweisung iteriert über alle enumerierbaren String-Eigenschaften eines Objekts (ignoring properties keyed by symbols), einschließlich geerbter enumerierbarer Eigenschaften.","popularity":0,"modified":"2022-08-14T03:39:57.000Z","other_translations":[{"locale":"en-US","title":"for...in","native":"English (US)"},{"locale":"es","title":"for...in","native":"Español"},{"locale":"fr","title":"for...in","native":"Français"},{"locale":"ja","title":"for...in","native":"日本語"},{"locale":"ko","title":"for...in","native":"한국어"},{"locale":"pt-BR","title":"for...in","native":"Português (do Brasil)"},{"locale":"ru","title":"for...in","native":"Русский"},{"locale":"zh-CN","title":"for...in","native":"中文 (简体)"},{"locale":"zh-TW","title":"for...in","native":"正體中文 (繁體)"}],"pageType":"unknown","source":{"folder":"de/web/javascript/reference/statements/for...in","github_url":"https://github.com/mdn/translated-content/blob/main/files/de/web/javascript/reference/statements/for...in/index.md","last_commit_url":"https://github.com/mdn/translated-content/commit/aebcbfc2355fccddc193e6b25ba720935bf90172","filename":"index.md"},"short_title":"for...in","parents":[{"uri":"/de/docs/Web","title":"Web-Technologien für Entwickler"},{"uri":"/de/docs/Web/JavaScript","title":"JavaScript"},{"uri":"/de/docs/Web/JavaScript/Reference","title":"JavaScript-Referenz"},{"uri":"/de/docs/Web/JavaScript/Reference/Statements","title":"Statements und Deklarationen"},{"uri":"/de/docs/Web/JavaScript/Reference/Statements/for...in","title":"for...in"}],"pageTitle":"for...in - JavaScript | MDN","noIndexing":false}}</script></body></html>