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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">在本文中</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#教程">教程</a></li><li class="document-toc-item "><a class="document-toc-link" href="#参考">参考</a></li></ul></section></div></div><div class="sidebar-body"> <ol> <li class="section"><em><a href="/zh-CN/docs/Web/JavaScript" aria-current="page">JavaScript</a></em></li> <li class="section">教程</li> <li class="toggle"> <details> <summary>快速入门</summary> <ol> <li><a href="/zh-CN/docs/Learn/Getting_started_with_the_web/JavaScript_basics">JavaScript 基础知识</a></li> <li><a href="/zh-CN/docs/Learn/JavaScript/First_steps">JavaScript 第一步</a></li> <li><a href="/zh-CN/docs/Learn/JavaScript/Building_blocks">构建 JavaScript 代码块</a></li> <li><a href="/zh-CN/docs/Learn/JavaScript/Objects">介绍 JavaScript 对象</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>JavaScript 指南</summary> <ol> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Introduction">介绍</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Grammar_and_types">语法和数据类型</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Control_flow_and_error_handling">流程控制与错误处理</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Loops_and_iteration">循环与迭代</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Functions">函数</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Expressions_and_operators">表达式与运算符</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Numbers_and_dates">数字和日期</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Text_formatting">文本格式化</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Regular_expressions">正则表达式</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Indexed_collections">索引集合类</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Keyed_collections">带键的集合</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Working_with_objects">使用对象</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Using_classes">使用类</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Using_promises">使用 Promise</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Typed_arrays">JavaScript 类型化数组</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Iterators_and_generators">迭代器和生成器</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Meta_programming">元编程</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Guide/Modules">JavaScript 模块</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>中级</summary> <ol> <li><a href="/zh-CN/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks">客户端 JavaScript 框架</a></li> <li><a href="/zh-CN/docs/Learn/JavaScript/Client-side_web_APIs">客户端 Web API</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Language_overview">语言概述</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Data_structures">JavaScript 数据结构</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Equality_comparisons_and_sameness">如何正确判断相等性</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Enumerability_and_ownership_of_properties">属性的可枚举性和所有权</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Closures">闭包</a></li> </ol> </details> </li> <li class="toggle"> <details> <summary>高级</summary> <ol> <li><a href="/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain">继承和原型链</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Memory_management">内存管理</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Event_loop">并发模型与事件循环</a></li> </ol> </details> </li> <li class="section"><a href="/zh-CN/docs/Web/JavaScript/Reference">参考</a></li> <li class="toggle"> <details> <summary>内置对象</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects">JavaScript 标准内置对象</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AggregateError">AggregateError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array">Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncFunction">AsyncFunction</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncGenerator">AsyncGenerator</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncGeneratorFunction">AsyncGeneratorFunction</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncIterator">AsyncIterator</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Atomics">Atomics</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigInt">BigInt</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigInt64Array">BigInt64Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigUint64Array">BigUint64Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Boolean">Boolean</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Date">Date</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/decodeURI">decodeURI()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent">decodeURIComponent()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/encodeURI">encodeURI()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent">encodeURIComponent()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Error">Error</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/escape">escape()</a><abbr class="icon icon-deprecated" title="已弃用。请不要在新的网站中使用。"> <span class="visually-hidden">已弃用</span> </abbr></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/eval">eval()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/EvalError">EvalError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry">FinalizationRegistry</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float16Array">Float16Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float32Array">Float32Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float64Array">Float64Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function">Function</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Generator">Generator</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/GeneratorFunction">GeneratorFunction</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/globalThis">globalThis</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Infinity">Infinity</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int16Array">Int16Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int32Array">Int32Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int8Array">Int8Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/InternalError">InternalError</a><abbr class="icon icon-nonstandard" title="非标准。请在使用前检查跨浏览器支持。"> <span class="visually-hidden">非标准</span> </abbr></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Intl">Intl</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/isFinite">isFinite()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/isNaN">isNaN()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Iterator">Iterator</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON">JSON</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Map">Map</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Math">Math</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/NaN">NaN</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Number">Number</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object">Object</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/parseFloat">parseFloat</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/parseInt">parseInt</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Promise">Promise</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy">Proxy</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RangeError">RangeError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError">ReferenceError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect">Reflect</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp">RegExp</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Set">Set</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer">SharedArrayBuffer</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String">String</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Symbol">Symbol</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError">SyntaxError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/TypeError">TypeError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array">Uint16Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array">Uint32Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array">Uint8Array</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint8ClampedArray">Uint8ClampedArray</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/undefined">undefined</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/unescape">unescape()</a><abbr class="icon icon-deprecated" title="已弃用。请不要在新的网站中使用。"> <span class="visually-hidden">已弃用</span> </abbr></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/URIError">URIError</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakMap">WeakMap</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakRef">WeakRef</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakSet">WeakSet</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>表达式和运算符</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators">表达式和运算符</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Addition">加法（+）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Addition_assignment">加法赋值（+=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Assignment">赋值（=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/async_function">异步函数（async function）表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/async_function*">async function* 表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/await">await</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_AND">按位与（&）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_AND_assignment">按位与赋值（&=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT">按位非（~）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_OR">按位或（|）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_OR_assignment">按位或赋值（|=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR">按位异或（^）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR_assignment">按位异或赋值 (^=)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/class">类表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Comma_operator">逗号运算符（,）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Conditional_operator">条件（三元）运算符</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Decrement">自减（--）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/delete">delete 运算符</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment">解构赋值</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Division">除法（/）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Division_assignment">除法赋值（/=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Equality">相等（==）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Exponentiation">幂（**）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Exponentiation_assignment">幂赋值（**=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/function">函数表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/function*">function* 表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Greater_than">大于（>）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Greater_than_or_equal">大于等于（>=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Grouping">圆括号运算符</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/import.meta">import.meta</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/import">import()</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/in">in</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Increment">自增（++）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Inequality">不相等（!=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/instanceof">instanceof</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Left_shift">左移 (<<)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Left_shift_assignment">左移赋值（<<=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Less_than">小于（<）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Less_than_or_equal">小于等于（<=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_AND">逻辑与（&&）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment">逻辑与赋值（&&=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_NOT">逻辑非（!）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_OR">逻辑或（||）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment">逻辑或赋值（||=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Multiplication">乘法（*）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Multiplication_assignment">乘法赋值（*=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/new">new</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/new.target">new.target</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/null">null</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_assignment">逻辑空赋值（??=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing">空值合并运算符（??）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Object_initializer">对象初始化器</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Operator_precedence">运算符优先级</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Optional_chaining">可选链运算符（?.）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Property_accessors">属性访问器</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Remainder">取余（%）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Remainder_assignment">取余赋值（%=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Right_shift">右移（>>）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Right_shift_assignment">右移赋值（>>=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Spread_syntax">展开语法</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Strict_equality">严格相等（===）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Strict_inequality">严格不相等（!==）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Subtraction">减法（-）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Subtraction_assignment">减法赋值（-=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/super">super</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/this">this</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof">typeof</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Unary_negation">一元减（-）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Unary_plus">一元加（+）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift">无符号右移（>>>）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment">无符号右移赋值（>>>=）</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/void">void 运算符</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/yield">yield</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/yield*">yield*</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>语句和声明</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements">语句和声明</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/async_function">async function</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/async_function*">async function*</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/block">块语句</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/break">break</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/class">class</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/const">const</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/continue">continue</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/debugger">debugger</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/do...while">do...while</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/Empty">空语句</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/export">export</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/Expression_statement">表达式语句</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for">for</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for-await...of">for await...of</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in">for...in</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for...of">for...of</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/function">function</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/function*">function*</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/if...else">if...else</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/import">import</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/label">label</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/let">let</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/return">return</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/switch">switch</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/throw">throw</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/try...catch">try...catch</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/var">var</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/while">while</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/with">with</a><abbr class="icon icon-deprecated" title="已弃用。请不要在新的网站中使用。"> <span class="visually-hidden">已弃用</span> </abbr></li></ol> </details> </li> <li class="toggle"> <details> <summary>函数</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions">函数</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/Arrow_functions">箭头函数表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/Default_parameters">默认参数值</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/get">getter</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/Method_definitions">方法的定义</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/rest_parameters">剩余参数</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/set">setter</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions/arguments">Arguments 对象</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>类</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes">类</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/constructor">构造函数</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/extends">extends</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/Private_properties">私有属性</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/Public_class_fields">公有类字段</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/static">static</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks">静态初始化块</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>正则表达式</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions">正则表达式</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Backreference">Backreference: \1, \2</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Capturing_group">Capturing group: (...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape">Character class escape: \d, \D, \w, \W, \s, \S</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_class">Character class: [...], [^...]</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape">Character escape: \n, \u{...}</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Disjunction">Disjunction: |</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Input_boundary_assertion">Input boundary assertion: ^, $</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Literal_character">Literal character: a, b</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Lookahead_assertion">Lookahead assertion: (?=...), (?!...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Lookbehind_assertion">Lookbehind assertion: (?<=...), (?<!...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Modifier">Modifier: (?ims-ims:...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Named_backreference">Named backreference: \k<name></a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Named_capturing_group">Named capturing group: (?<name>...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Non-capturing_group">Non-capturing group: (?:...)</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Quantifier">量词：*、+、?、{n}、{n,}、{n,m}</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape">Unicode 字符类转义：\p{...}、\P{...}</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Wildcard">Wildcard: .</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Word_boundary_assertion">Word boundary assertion: \b, \B</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>错误</summary> <ol><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors">JavaScript 错误参考</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Promise_any_all_rejected">AggregateError: No Promise in Promise.any was resolved</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Property_access_denied">Error: Permission denied to access property "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Too_much_recursion">InternalError: too much recursion</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_valid_code_point">RangeError: argument is not a valid code point</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_division_by_zero">RangeError: BigInt division by zero</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_negative_exponent">RangeError: BigInt negative exponent</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Form_must_be_one_of">RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD'</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_array_length">RangeError: invalid array length</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_date">RangeError: invalid date</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Precision_range">RangeError: precision is out of range</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_radix">RangeError: radix must be an integer</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Resulting_string_too_large">RangeError: repeat count must be less than infinity</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Negative_repetition_count">RangeError: repeat count must be non-negative</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_be_converted_to_BigInt_because_it_isnt_an_integer">RangeError: x can't be converted to BigInt because it isn't an integer</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_defined">ReferenceError: "x" is not defined</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Undeclared_var">ReferenceError: assignment to undeclared variable "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_access_lexical_declaration_before_init">ReferenceError: can't access lexical declaration`X' before initialization</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_caller_or_arguments_usage">ReferenceError: deprecated caller or arguments usage</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Super_not_called">ReferenceError: must call super constructor before using 'this' in derived class constructor</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Super_called_twice">ReferenceError: super() called twice in derived class constructor</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_strict_arguments_eval">SyntaxError: 'arguments'/'eval' can't be defined or assigned to in strict mode code</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_literal">SyntaxError: "0"-prefixed octal literals are deprecated</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Strict_non_simple_params">SyntaxError: "use strict" not allowed in function with non-simple parameters</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Reserved_identifier">SyntaxError: "x" is a reserved identifier</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_backslash_at_end_of_pattern">SyntaxError: \ at end of pattern</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_for-of_initializer">SyntaxError: a declaration in the head of a for-of loop can't have an initializer</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Delete_in_strict_mode">SyntaxError: applying the 'delete' operator to an unqualified name is deprecated</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Arguments_not_allowed">SyntaxError: arguments is not valid in fields</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_await">SyntaxError: await is only valid in async functions, async generators and modules</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/await_yield_in_parameter">SyntaxError: await/yield expression can't be used in parameter</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_use_nullish_coalescing_unparenthesized">SyntaxError: cannot use `??` unparenthesized within `||` and `&&` expressions</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_character_class_escape_in_class_range">SyntaxError: character class escape cannot be used in class range in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_continue">SyntaxError: continue must be inside loop</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_duplicate_capture_group_name">SyntaxError: duplicate capture group name in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Duplicate_parameter">SyntaxError: duplicate formal argument x</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer">SyntaxError: for-in loop head declarations may not have initializers</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Unnamed_function_statement">SyntaxError: function statement requires a name</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Function_label">SyntaxError: functions cannot be labelled</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Either_be_both_static_or_non-static">SyntaxError: getter and setter for private name #x should either be both static or non-static</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Getter_no_arguments">SyntaxError: getter functions must have no arguments</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Identifier_after_number">SyntaxError: identifier starts immediately after numeric literal</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Illegal_character">SyntaxError: illegal character</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/import_decl_module_top_level">SyntaxError: import declarations may only appear at top level of a module</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_incomplete_quantifier">SyntaxError: incomplete quantifier in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_assignment_left-hand_side">SyntaxError: invalid assignment left-hand side</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_BigInt_syntax">SyntaxError: invalid BigInt syntax</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_capture_group_name">SyntaxError: invalid capture group name in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_char_in_class">SyntaxError: invalid character in class in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_class_set_operation">SyntaxError: invalid class set operation in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_decimal_escape">SyntaxError: invalid decimal escape in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_identity_escape">SyntaxError: invalid identity escape in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_named_capture_reference">SyntaxError: invalid named capture reference in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_property_name">SyntaxError: invalid property name in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_range_in_character_class">SyntaxError: invalid range in character class</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_group">SyntaxError: invalid regexp group</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_regexp_flag">SyntaxError: invalid regular expression flag "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_unicode_escape">SyntaxError: invalid unicode escape in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/JSON_bad_parse">SyntaxError: JSON.parse: bad parsing</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Label_not_found">SyntaxError: label not found</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_colon_after_property_id">SyntaxError: missing : after property id</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_argument_list">SyntaxError: missing ) after argument list</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_condition">SyntaxError: missing ) after condition</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_bracket_after_list">SyntaxError: missing ] after element list</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_function_body">SyntaxError: missing } after function body</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_property_list">SyntaxError: missing } after property list</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_initializer_in_const">SyntaxError: missing = in const declaration</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_formal_parameter">SyntaxError: missing formal parameter</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_name_after_dot_operator">SyntaxError: missing name after . operator</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/No_variable_name">SyntaxError: missing variable name</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_negated_char_class_with_strings">SyntaxError: negated character class with strings in regular expression</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_new_optional">SyntaxError: new keyword cannot be used with an optional chain</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_nothing_to_repeat">SyntaxError: nothing to repeat</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_numbers_out_of_order_in_quantifier">SyntaxError: numbers out of order in {} quantifier.</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_escape_sequence">SyntaxError: octal escape sequences can't be used in untagged template literals or in strict mode code</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Parameter_after_rest_parameter">SyntaxError: parameter after rest parameter</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_delete_private_fields">SyntaxError: private fields can't be deleted</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Duplicate_proto">SyntaxError: property name __proto__ appears more than once in object literal</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_raw_bracket">SyntaxError: raw bracket is not allowed in regular expression with unicode flag</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Redeclared_parameter">SyntaxError: redeclaration of formal parameter "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Undeclared_private_field_or_method">SyntaxError: reference to undeclared private field or method #x</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Rest_with_default">SyntaxError: rest parameter may not have a default</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_return">SyntaxError: return not in function</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Setter_one_argument">SyntaxError: setter functions must have one argument</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/String_literal_EOL">SyntaxError: string literal contains an unescaped line break</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_super_call">SyntaxError: super() is only valid in derived class constructors</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_optional_template">SyntaxError: tagged template cannot be used with optional chain</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Hash_outside_class">SyntaxError: Unexpected '#' used outside of class body</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Unexpected_token">SyntaxError: Unexpected token</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_break">SyntaxError: unlabeled break must be inside loop or switch</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Unparenthesized_unary_expr_lhs_exponentiation">SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**'</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_super_prop">SyntaxError: use of super property/member accesses only valid within methods or eval code within methods</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_source_map_pragma">SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/is_not_iterable">TypeError: 'x' is not iterable</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Unexpected_type">TypeError: "x" is (not) "y"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_constructor">TypeError: "x" is not a constructor</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_function">TypeError: "x" is not a function</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/No_non-null_object">TypeError: "x" is not a non-null object</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Read-only">TypeError: "x" is read-only</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_not_serializable">TypeError: BigInt value can't be serialized in JSON</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Builtin_ctor_no_new">TypeError: calling a builtin X constructor without new is forbidden</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Get_set_missing_private">TypeError: can't access/set private field or method: object is not the right class</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_assign_to_property">TypeError: can't assign to property "x" on "y": not an object</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_convert_BigInt_to_number">TypeError: can't convert BigInt to number</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_convert_x_to_BigInt">TypeError: can't convert x to BigInt</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_define_property_object_not_extensible">TypeError: can't define property "x": "obj" is not extensible</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Non_configurable_array_element">TypeError: can't delete non-configurable array element</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_redefine_property">TypeError: can't redefine non-configurable property "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_set_prototype">TypeError: can't set prototype of this object</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cyclic_prototype">TypeError: can't set prototype: it would cause a prototype chain cycle</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/in_operator_no_object">TypeError: invalid 'in' operand "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Class_ctor_no_new">TypeError: class constructors must be invoked with 'new'</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value">TypeError: cyclic object value</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_derived_return">TypeError: derived class constructor returned invalid value x</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Private_setter_only">TypeError: getting private setter-only property</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Private_double_initialization">TypeError: Initializing an object twice is an error with private fields/methods</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/invalid_right_hand_side_instanceof_operand">TypeError: invalid 'instanceof' operand 'x'</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Array_sort_argument">TypeError: invalid Array.prototype.sort argument</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_const_assignment">TypeError: invalid assignment to const "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Constructor_cant_be_used_directly">TypeError: Iterator/AsyncIterator constructor can't be used directly</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Requires_global_RegExp">TypeError: matchAll/replaceAll must be called with a global RegExp</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/More_arguments_needed">TypeError: More arguments needed</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/No_properties">TypeError: "x" has no properties</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_delete">TypeError: property "x" is non-configurable and can't be deleted</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Reduce_of_empty_array_with_no_initial_value">TypeError: Reduce of empty array with no initial value</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Getter_only">TypeError: setting getter-only property "x"</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Key_not_weakly_held">TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Called_on_incompatible_type">X.prototype.y called on incompatible type</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Malformed_URI">URIError: malformed URI sequence</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Already_has_pragma">Warning: -file- is being assigned a //# sourceMappingURL, but already has one</a></li><li><a href="/zh-CN/docs/Web/JavaScript/Reference/Errors/Stmt_after_return">Warning: unreachable code after return statement</a></li></ol> </details> </li> <li class="toggle"> <details> <summary>更多</summary> <ol> <li><a href="/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview">JavaScript 技术概要</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Lexical_grammar">词法文法</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Iteration_protocols">迭代协议</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Strict_mode">严格模式</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Template_literals">模板字符串</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Trailing_commas">尾后逗号</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features">已废弃的特性</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">在本文中</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#教程">教程</a></li><li class="document-toc-item "><a class="document-toc-link" href="#参考">参考</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="zh-CN"><header><h1>JavaScript</h1></header><div class="section-content"><p><strong>JavaScript</strong>（<strong>JS</strong>）是一种具有<a href="/zh-CN/docs/Glossary/First-class_Function">函数优先</a>特性的轻量级、解释型或者说<a href="https://zh.wikipedia.org/wiki/%E5%8D%B3%E6%99%82%E7%B7%A8%E8%AD%AF" class="external" target="_blank">即时编译型</a>的编程语言。虽然作为 Web 页面中的脚本语言被人所熟知，但是它也被用到了很多<a href="https://zh.wikipedia.org/wiki/JavaScript#%E5%85%B6%E4%BB%96" class="external" target="_blank">非浏览器环境</a>中，例如 <a href="/zh-CN/docs/Glossary/Node.js">Node.js</a>、<a href="https://couchdb.apache.org" class="external" target="_blank">Apache CouchDB</a>、<a href="https://opensource.adobe.com/dc-acrobat-sdk-docs/acrobatsdk/" class="external" target="_blank">Adobe Acrobat</a> 等。进一步说，JavaScript 是一种<a href="/zh-CN/docs/Glossary/Prototype-based_programming">基于原型</a>、多范式、<a href="/zh-CN/docs/Glossary/Thread">单线程</a>的<a href="/zh-CN/docs/Glossary/Dynamic_typing">动态</a>语言，并且支持面向对象、命令式和声明式（如函数式编程）风格。</p> <p>JavaScript 的动态特性包括运行时对象的构造、变量参数列表、函数变量、动态脚本创建（通过 <a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/eval"><code>eval</code></a>）、对象内枚举（通过 <a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in"><code>for...in</code></a> 和 <a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object#%E9%9D%99%E6%80%81%E6%96%B9%E6%B3%95"><code>Object</code> 工具方法</a>）和源代码恢复（JavaScript 函数会存储其源代码文本，可以使用 <a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/toString"><code>toString()</code></a> 进行检索）。</p> <p>本部分文档将专注于 JavaScript 语言本身，而不是专注于 Web 页面或其他宿主环境特有的那部分。想要了解 Web 页面特有的 <a href="/zh-CN/docs/Glossary/API">API</a> 信息，请参考 <a href="/zh-CN/docs/Web/API">Web API</a> 以及 <a href="/zh-CN/docs/Glossary/DOM">DOM</a>。</p> <p>JavaScript 标准是 <a href="https://tc39.es/ecma262/" class="external" target="_blank">ECMAScript 语言规范</a>（ECMA-262）和 <a href="https://tc39.es/ecma402/" class="external" target="_blank">ECMAScript 国际化 API 规范</a>（ECMA-402）。只要某个浏览器实现了某个特性，我们就会尝试详细记录这个特性。这意味着，当某个 <a href="https://github.com/tc39/proposals" class="external" target="_blank">ECMAScript 新特性的提案</a>在浏览器中实现时，文档和 MDN 文章中的示例可能会使用这些新特性。大多数时候发生在<a href="https://tc39.es/process-document/" class="external" target="_blank">阶段</a> 3 和阶段 4 之间，通常在正式发布之前。</p> <p>不要将 JavaScript 与 <a href="https://zh.wikipedia.org/wiki/Java" class="external" target="_blank">Java 编程语言</a>弄混——<strong>JavaScript <em>不是</em>“解释型的 Java”</strong>。“Java”和“JavaScript”都是 Oracle 公司在美国和其他国家注册（或未注册）的商标。然而，这两门编程语言有着非常不同的语法、语义和用途。</p> <p>JavaScript 核心语言特性（大部分是纯 <a href="/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview">ECMAScript</a>）的文档包含以下内容：</p> <ul> <li><a href="/zh-CN/docs/Web/JavaScript/Guide">JavaScript 指南</a></li> <li><a href="/zh-CN/docs/Web/JavaScript/Reference">JavaScript 参考</a></li> </ul> <p>有关 JavaScript 规范和相关技术的更多信息，请参阅 <a href="/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview">JavaScript 技术概述</a>。</p></div><section aria-labelledby="教程"><h2 id="教程"><a href="#教程">教程</a></h2><div class="section-content"><p>借助指南和教程来学习如何用 JavaScript 编程。</p></div></section><section aria-labelledby="面向纯新手"><h3 id="面向纯新手"><a href="#面向纯新手">面向纯新手</a></h3><div class="section-content"><p>如果你想学习 JavaScript，却从未接触过 JavaScript 或编程，你可以投入到我们的 <a href="/zh-CN/docs/Learn/JavaScript">JavaScript 主题学习区</a>。下面列出了这部分的所有章节：</p> <dl> <dt id="javascript_第一步"><a href="/zh-CN/docs/Learn/JavaScript/First_steps">JavaScript 第一步</a></dt> <dd> <p>回答一些基本问题，比如“JavaScript 是什么？”、“它长什么样子？”、“它可以用来做什么？”等，还谈及如变量、字符串、数字、数组等 JavaScript 关键特性。</p> </dd> <dt id="创建_javascript_代码块"><a href="/zh-CN/docs/Learn/JavaScript/Building_blocks">创建 JavaScript 代码块</a></dt> <dd> <p>继续介绍 JavaScript 的关键基本特性，将注意力转向常见的代码块类型，如条件语句、循环、函数、事件等。</p> </dd> <dt id="介绍_javascript_对象"><a href="/zh-CN/docs/Learn/JavaScript/Objects">介绍 JavaScript 对象</a></dt> <dd> <p>如果你想进一步提高对语言的了解并编写出更高效的代码，理解 JavaScript 面向对象的本质很重要，因此我们为你准备了这个模块。</p> </dd> <dt id="异步_javascript"><a href="/zh-CN/docs/Learn/JavaScript/Asynchronous">异步 JavaScript</a></dt> <dd> <p>探讨异步 JavaScript、为什么它很重要、如何使用它有效地处理潜在的阻塞操作（如从服务器获取资源）。</p> </dd> <dt id="客户端_web_api"><a href="/zh-CN/docs/Learn/JavaScript/Client-side_web_APIs">客户端 web API</a></dt> <dd> <p>探讨 API 是什么、如何使用一些开发工作中最常见的 API。</p> </dd> </dl></div></section><section aria-labelledby="javascript_指南"><h3 id="javascript_指南"><a href="#javascript_指南">JavaScript 指南</a></h3><div class="section-content"><dl> <dt id="javascript_指南_2"><a href="/zh-CN/docs/Web/JavaScript/Guide">JavaScript 指南</a></dt> <dd> <p>一份非常详细的 JavaScript 指南，适用于有过 JavaScript 或其他语言编程经验的读者。</p> </dd> </dl></div></section><section aria-labelledby="中级"><h3 id="中级"><a href="#中级">中级</a></h3><div class="section-content"><dl> <dt id="理解客户端_javascript_框架"><a href="/zh-CN/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks">理解客户端 Javascript 框架</a></dt> <dd> <p>JavaScript 框架是现代前端 Web 开发必不可少的一部分，为开发者构建可扩展、交互式的 Web 应用程序提供了经过验证的工具。这个模块讨论一些客户端框架如何工作以及如何集成到工具集的基础背景知识，接着是一个讨论现在最流行框架的系列教程。</p> </dd> <dt id="javascript_语言概述"><a href="/zh-CN/docs/Web/JavaScript/Language_overview">JavaScript 语言概述</a></dt> <dd> <p>JavaScript 基础语法和语义概述：帮助来自其他编程语言的读者加速学习。</p> </dd> <dt id="javascript_数据结构"><a href="/zh-CN/docs/Web/JavaScript/Data_structures">JavaScript 数据结构</a></dt> <dd> <p>JavaScript 数据结构概述。</p> </dd> <dt id="相等比较和相同"><a href="/zh-CN/docs/Web/JavaScript/Equality_comparisons_and_sameness">相等比较和相同</a></dt> <dd> <p>JavaScript 提供了三种不同的值比较运算：严格相等运算符 <code>===</code>、非严格相等运算符 <code>==</code>，以及 <a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/is"><code>Object.is()</code></a> 方法。</p> </dd> <dt id="属性的可枚举性和所有权"><a href="/zh-CN/docs/Web/JavaScript/Enumerability_and_ownership_of_properties">属性的可枚举性和所有权</a></dt> <dd> <p>不同的处理属性的可枚举性和所有权的方法——一个接着一个的访问一组对象属性。</p> </dd> <dt id="闭包"><a href="/zh-CN/docs/Web/JavaScript/Closures">闭包</a></dt> <dd> <p>闭包是由函数及其声明所在的词法环境结合而成。</p> </dd> </dl></div></section><section aria-labelledby="高级"><h3 id="高级"><a href="#高级">高级</a></h3><div class="section-content"><dl> <dt id="继承与原型链"><a href="/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain">继承与原型链</a></dt> <dd> <p>解释被广泛误解与低估的基于原型的继承。</p> </dd> <dt id="内存管理"><a href="/zh-CN/docs/Web/JavaScript/Memory_management">内存管理</a></dt> <dd> <p>JavaScript 的内存生命周期和垃圾回收。</p> </dd> <dt id="事件循环"><a href="/zh-CN/docs/Web/JavaScript/Event_loop">事件循环</a></dt> <dd> <p>JavaScript 拥有基于“事件循环”的运行时模型。</p> </dd> </dl></div></section><section aria-labelledby="参考"><h2 id="参考"><a href="#参考">参考</a></h2><div class="section-content"><p>浏览完整的 <a href="/zh-CN/docs/Web/JavaScript/Reference">JavaScript 参考</a>文档。</p> <dl> <dt id="标准对象"><a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects">标准对象</a></dt> <dd> <p>了解 <a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array"><code>Array</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Boolean"><code>Boolean</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Date"><code>Date</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Error"><code>Error</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function"><code>Function</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON"><code>JSON</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Math"><code>Math</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Number"><code>Number</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object"><code>Object</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp"><code>RegExp</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String"><code>String</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Map"><code>Map</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Set"><code>Set</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakMap"><code>WeakMap</code></a> 、<a href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakSet"><code>WeakSet</code></a> 等标准内置对象。</p> </dd> <dt id="表达式和运算符"><a href="/zh-CN/docs/Web/JavaScript/Reference/Operators">表达式和运算符</a></dt> <dd> <p>学习运算符 <a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/instanceof"><code>instanceof</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof"><code>typeof</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/new"><code>new</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/this"><code>this</code></a>，<a href="/zh-CN/docs/Web/JavaScript/Reference/Operators/Operator_precedence">运算符优先级</a>，以及其他运算符的行为。</p> </dd> <dt id="语句和声明"><a href="/zh-CN/docs/Web/JavaScript/Reference/Statements">语句和声明</a></dt> <dd> <p>学习 <a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/do...while"><code>do-while</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in"><code>for-in</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/for...of"><code>for-of</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/try...catch"><code>try-catch</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/let"><code>let</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/var"><code>var</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/const"><code>const</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/if...else"><code>if-else</code></a>、<a href="/zh-CN/docs/Web/JavaScript/Reference/Statements/switch"><code>switch</code></a> 以及其他语句和关键字的作用。</p> </dd> <dt id="函数"><a href="/zh-CN/docs/Web/JavaScript/Reference/Functions">函数</a></dt> <dd> <p>学习如何使用 JavaScript 函数开发应用。</p> </dd> <dt id="类"><a href="/zh-CN/docs/Web/JavaScript/Reference/Classes">类</a></dt> <dd> <p>JavaScript 类是最适合面向对象编程的方式。</p> </dd> </dl></div></section></article><aside class="article-footer"><div class="article-footer-inner"><div 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对象</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>JavaScript 指南</summary>\n <ol>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Introduction\">介绍</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Grammar_and_types\">语法和数据类型</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Control_flow_and_error_handling\">流程控制与错误处理</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Loops_and_iteration\">循环与迭代</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Functions\">函数</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Expressions_and_operators\">表达式与运算符</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Numbers_and_dates\">数字和日期</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Text_formatting\">文本格式化</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Regular_expressions\">正则表达式</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Indexed_collections\">索引集合类</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Keyed_collections\">带键的集合</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Working_with_objects\">使用对象</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Using_classes\">使用类</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Using_promises\">使用 Promise</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Typed_arrays\">JavaScript 类型化数组</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Iterators_and_generators\">迭代器和生成器</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Meta_programming\">元编程</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide/Modules\">JavaScript 模块</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>中级</summary>\n <ol>\n <li><a href=\"/zh-CN/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks\">客户端 JavaScript 框架</a></li>\n <li><a href=\"/zh-CN/docs/Learn/JavaScript/Client-side_web_APIs\">客户端 Web API</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Language_overview\">语言概述</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Data_structures\">JavaScript 数据结构</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Equality_comparisons_and_sameness\">如何正确判断相等性</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Enumerability_and_ownership_of_properties\">属性的可枚举性和所有权</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Closures\">闭包</a></li>\n </ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>高级</summary>\n <ol>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain\">继承和原型链</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Memory_management\">内存管理</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Event_loop\">并发模型与事件循环</a></li>\n </ol>\n </details>\n </li>\n <li class=\"section\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference\">参考</a></li>\n <li class=\"toggle\">\n <details>\n <summary>内置对象</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects\">JavaScript 标准内置对象</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AggregateError\">AggregateError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array\">Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer\">ArrayBuffer</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncFunction\">AsyncFunction</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncGenerator\">AsyncGenerator</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncGeneratorFunction\">AsyncGeneratorFunction</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/AsyncIterator\">AsyncIterator</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Atomics\">Atomics</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigInt\">BigInt</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigInt64Array\">BigInt64Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/BigUint64Array\">BigUint64Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Boolean\">Boolean</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/DataView\">DataView</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Date\">Date</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/decodeURI\">decodeURI()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent\">decodeURIComponent()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/encodeURI\">encodeURI()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent\">encodeURIComponent()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Error\">Error</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/escape\">escape()</a><abbr class=\"icon icon-deprecated\" title=\"已弃用。请不要在新的网站中使用。\">\n <span class=\"visually-hidden\">已弃用</span>\n</abbr></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/eval\">eval()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/EvalError\">EvalError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry\">FinalizationRegistry</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float16Array\">Float16Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float32Array\">Float32Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Float64Array\">Float64Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function\">Function</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Generator\">Generator</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/GeneratorFunction\">GeneratorFunction</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/globalThis\">globalThis</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Infinity\">Infinity</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int16Array\">Int16Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int32Array\">Int32Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Int8Array\">Int8Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/InternalError\">InternalError</a><abbr class=\"icon icon-nonstandard\" title=\"非标准。请在使用前检查跨浏览器支持。\">\n <span class=\"visually-hidden\">非标准</span>\n</abbr></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Intl\">Intl</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/isFinite\">isFinite()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/isNaN\">isNaN()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Iterator\">Iterator</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON\">JSON</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Map\">Map</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Math\">Math</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/NaN\">NaN</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Number\">Number</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object\">Object</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/parseFloat\">parseFloat</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/parseInt\">parseInt</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Promise\">Promise</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Proxy\">Proxy</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RangeError\">RangeError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError\">ReferenceError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Reflect\">Reflect</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp\">RegExp</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Set\">Set</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer\">SharedArrayBuffer</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String\">String</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Symbol\">Symbol</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError\">SyntaxError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/TypedArray\">TypedArray</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/TypeError\">TypeError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array\">Uint16Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array\">Uint32Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array\">Uint8Array</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Uint8ClampedArray\">Uint8ClampedArray</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/undefined\">undefined</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/unescape\">unescape()</a><abbr class=\"icon icon-deprecated\" title=\"已弃用。请不要在新的网站中使用。\">\n <span class=\"visually-hidden\">已弃用</span>\n</abbr></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/URIError\">URIError</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakMap\">WeakMap</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakRef\">WeakRef</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakSet\">WeakSet</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>表达式和运算符</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators\">表达式和运算符</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Addition\">加法（+）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Addition_assignment\">加法赋值（+=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Assignment\">赋值（=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/async_function\">异步函数（async function）表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/async_function*\">async function* 表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/await\">await</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_AND\">按位与（&）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_AND_assignment\">按位与赋值（&=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT\">按位非（~）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_OR\">按位或（|）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_OR_assignment\">按位或赋值（|=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR\">按位异或（^）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Bitwise_XOR_assignment\">按位异或赋值 (^=)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/class\">类表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Comma_operator\">逗号运算符（,）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Conditional_operator\">条件（三元）运算符</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Decrement\">自减（--）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/delete\">delete 运算符</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment\">解构赋值</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Division\">除法（/）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Division_assignment\">除法赋值（/=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Equality\">相等（==）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Exponentiation\">幂（**）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Exponentiation_assignment\">幂赋值（**=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/function\">函数表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/function*\">function* 表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Greater_than\">大于（>）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Greater_than_or_equal\">大于等于（>=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Grouping\">圆括号运算符</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/import.meta\">import.meta</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/import\">import()</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/in\">in</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Increment\">自增（++）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Inequality\">不相等（!=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/instanceof\">instanceof</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Left_shift\">左移 (<<)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Left_shift_assignment\">左移赋值（<<=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Less_than\">小于（<）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Less_than_or_equal\">小于等于（<=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_AND\">逻辑与（&&）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment\">逻辑与赋值（&&=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_NOT\">逻辑非（!）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_OR\">逻辑或（||）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment\">逻辑或赋值（||=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Multiplication\">乘法（*）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Multiplication_assignment\">乘法赋值（*=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/new\">new</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/new.target\">new.target</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/null\">null</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_assignment\">逻辑空赋值（??=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing\">空值合并运算符（??）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Object_initializer\">对象初始化器</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Operator_precedence\">运算符优先级</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Optional_chaining\">可选链运算符（?.）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Property_accessors\">属性访问器</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Remainder\">取余（%）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Remainder_assignment\">取余赋值（%=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Right_shift\">右移（>>）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Right_shift_assignment\">右移赋值（>>=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Spread_syntax\">展开语法</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Strict_equality\">严格相等（===）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Strict_inequality\">严格不相等（!==）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Subtraction\">减法（-）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Subtraction_assignment\">减法赋值（-=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/super\">super</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/this\">this</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof\">typeof</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Unary_negation\">一元减（-）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Unary_plus\">一元加（+）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift\">无符号右移（>>>）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment\">无符号右移赋值（>>>=）</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/void\">void 运算符</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/yield\">yield</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/yield*\">yield*</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>语句和声明</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements\">语句和声明</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/async_function\">async function</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/async_function*\">async function*</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/block\">块语句</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/break\">break</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/class\">class</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/const\">const</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/continue\">continue</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/debugger\">debugger</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/do...while\">do...while</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/Empty\">空语句</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/export\">export</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/Expression_statement\">表达式语句</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for\">for</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for-await...of\">for await...of</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in\">for...in</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for...of\">for...of</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/function\">function</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/function*\">function*</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/if...else\">if...else</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/import\">import</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/label\">label</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/let\">let</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/return\">return</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/switch\">switch</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/throw\">throw</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/try...catch\">try...catch</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/var\">var</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/while\">while</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/with\">with</a><abbr class=\"icon icon-deprecated\" title=\"已弃用。请不要在新的网站中使用。\">\n <span class=\"visually-hidden\">已弃用</span>\n</abbr></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>函数</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions\">函数</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/Arrow_functions\">箭头函数表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/Default_parameters\">默认参数值</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/get\">getter</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/Method_definitions\">方法的定义</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/rest_parameters\">剩余参数</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/set\">setter</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions/arguments\">Arguments 对象</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>类</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes\">类</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/constructor\">构造函数</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/extends\">extends</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/Private_properties\">私有属性</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/Public_class_fields\">公有类字段</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/static\">static</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks\">静态初始化块</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>正则表达式</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions\">正则表达式</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Backreference\">Backreference: \\1, \\2</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Capturing_group\">Capturing group: (...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_class_escape\">Character class escape: \\d, \\D, \\w, \\W, \\s, \\S</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_class\">Character class: [...], [^...]</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Character_escape\">Character escape: \\n, \\u{...}</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Disjunction\">Disjunction: |</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Input_boundary_assertion\">Input boundary assertion: ^, $</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Literal_character\">Literal character: a, b</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Lookahead_assertion\">Lookahead assertion: (?=...), (?!...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Lookbehind_assertion\">Lookbehind assertion: (?<=...), (?<!...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Modifier\">Modifier: (?ims-ims:...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Named_backreference\">Named backreference: \\k<name></a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Named_capturing_group\">Named capturing group: (?<name>...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Non-capturing_group\">Non-capturing group: (?:...)</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Quantifier\">量词：*、+、?、{n}、{n,}、{n,m}</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Unicode_character_class_escape\">Unicode 字符类转义：\\p{...}、\\P{...}</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Wildcard\">Wildcard: .</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Regular_expressions/Word_boundary_assertion\">Word boundary assertion: \\b, \\B</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>错误</summary>\n <ol><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors\">JavaScript 错误参考</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Promise_any_all_rejected\">AggregateError: No Promise in Promise.any was resolved</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Property_access_denied\">Error: Permission denied to access property \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Too_much_recursion\">InternalError: too much recursion</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_valid_code_point\">RangeError: argument is not a valid code point</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_division_by_zero\">RangeError: BigInt division by zero</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_negative_exponent\">RangeError: BigInt negative exponent</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Form_must_be_one_of\">RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD'</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_array_length\">RangeError: invalid array length</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_date\">RangeError: invalid date</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Precision_range\">RangeError: precision is out of range</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_radix\">RangeError: radix must be an integer</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Resulting_string_too_large\">RangeError: repeat count must be less than infinity</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Negative_repetition_count\">RangeError: repeat count must be non-negative</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_be_converted_to_BigInt_because_it_isnt_an_integer\">RangeError: x can't be converted to BigInt because it isn't an integer</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_defined\">ReferenceError: \"x\" is not defined</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Undeclared_var\">ReferenceError: assignment to undeclared variable \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_access_lexical_declaration_before_init\">ReferenceError: can't access lexical declaration`X' before initialization</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_caller_or_arguments_usage\">ReferenceError: deprecated caller or arguments usage</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Super_not_called\">ReferenceError: must call super constructor before using 'this' in derived class constructor</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Super_called_twice\">ReferenceError: super() called twice in derived class constructor</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_strict_arguments_eval\">SyntaxError: 'arguments'/'eval' can't be defined or assigned to in strict mode code</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_literal\">SyntaxError: \"0\"-prefixed octal literals are deprecated</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Strict_non_simple_params\">SyntaxError: \"use strict\" not allowed in function with non-simple parameters</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Reserved_identifier\">SyntaxError: \"x\" is a reserved identifier</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_backslash_at_end_of_pattern\">SyntaxError: \\ at end of pattern</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_for-of_initializer\">SyntaxError: a declaration in the head of a for-of loop can't have an initializer</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Delete_in_strict_mode\">SyntaxError: applying the 'delete' operator to an unqualified name is deprecated</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Arguments_not_allowed\">SyntaxError: arguments is not valid in fields</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_await\">SyntaxError: await is only valid in async functions, async generators and modules</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/await_yield_in_parameter\">SyntaxError: await/yield expression can't be used in parameter</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_use_nullish_coalescing_unparenthesized\">SyntaxError: cannot use `??` unparenthesized within `||` and `&&` expressions</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_character_class_escape_in_class_range\">SyntaxError: character class escape cannot be used in class range in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_continue\">SyntaxError: continue must be inside loop</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_duplicate_capture_group_name\">SyntaxError: duplicate capture group name in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Duplicate_parameter\">SyntaxError: duplicate formal argument x</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_for-in_initializer\">SyntaxError: for-in loop head declarations may not have initializers</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Unnamed_function_statement\">SyntaxError: function statement requires a name</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Function_label\">SyntaxError: functions cannot be labelled</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Either_be_both_static_or_non-static\">SyntaxError: getter and setter for private name #x should either be both static or non-static</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Getter_no_arguments\">SyntaxError: getter functions must have no arguments</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Identifier_after_number\">SyntaxError: identifier starts immediately after numeric literal</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Illegal_character\">SyntaxError: illegal character</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/import_decl_module_top_level\">SyntaxError: import declarations may only appear at top level of a module</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_incomplete_quantifier\">SyntaxError: incomplete quantifier in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_assignment_left-hand_side\">SyntaxError: invalid assignment left-hand side</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_BigInt_syntax\">SyntaxError: invalid BigInt syntax</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_capture_group_name\">SyntaxError: invalid capture group name in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_char_in_class\">SyntaxError: invalid character in class in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_class_set_operation\">SyntaxError: invalid class set operation in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_decimal_escape\">SyntaxError: invalid decimal escape in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_identity_escape\">SyntaxError: invalid identity escape in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_named_capture_reference\">SyntaxError: invalid named capture reference in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_property_name\">SyntaxError: invalid property name in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_range_in_character_class\">SyntaxError: invalid range in character class</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_group\">SyntaxError: invalid regexp group</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_regexp_flag\">SyntaxError: invalid regular expression flag \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_invalid_unicode_escape\">SyntaxError: invalid unicode escape in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/JSON_bad_parse\">SyntaxError: JSON.parse: bad parsing</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Label_not_found\">SyntaxError: label not found</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_colon_after_property_id\">SyntaxError: missing : after property id</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_argument_list\">SyntaxError: missing ) after argument list</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_parenthesis_after_condition\">SyntaxError: missing ) after condition</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_bracket_after_list\">SyntaxError: missing ] after element list</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_function_body\">SyntaxError: missing } after function body</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_curly_after_property_list\">SyntaxError: missing } after property list</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_initializer_in_const\">SyntaxError: missing = in const declaration</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_formal_parameter\">SyntaxError: missing formal parameter</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Missing_name_after_dot_operator\">SyntaxError: missing name after . operator</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/No_variable_name\">SyntaxError: missing variable name</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_negated_char_class_with_strings\">SyntaxError: negated character class with strings in regular expression</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_new_optional\">SyntaxError: new keyword cannot be used with an optional chain</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_nothing_to_repeat\">SyntaxError: nothing to repeat</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_numbers_out_of_order_in_quantifier\">SyntaxError: numbers out of order in {} quantifier.</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_escape_sequence\">SyntaxError: octal escape sequences can't be used in untagged template literals or in strict mode code</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Parameter_after_rest_parameter\">SyntaxError: parameter after rest parameter</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_delete_private_fields\">SyntaxError: private fields can't be deleted</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Duplicate_proto\">SyntaxError: property name __proto__ appears more than once in object literal</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Regex_raw_bracket\">SyntaxError: raw bracket is not allowed in regular expression with unicode flag</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Redeclared_parameter\">SyntaxError: redeclaration of formal parameter \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Undeclared_private_field_or_method\">SyntaxError: reference to undeclared private field or method #x</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Rest_with_default\">SyntaxError: rest parameter may not have a default</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_return\">SyntaxError: return not in function</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Setter_one_argument\">SyntaxError: setter functions must have one argument</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/String_literal_EOL\">SyntaxError: string literal contains an unescaped line break</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_super_call\">SyntaxError: super() is only valid in derived class constructors</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_optional_template\">SyntaxError: tagged template cannot be used with optional chain</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Hash_outside_class\">SyntaxError: Unexpected '#' used outside of class body</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Unexpected_token\">SyntaxError: Unexpected token</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_break\">SyntaxError: unlabeled break must be inside loop or switch</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Unparenthesized_unary_expr_lhs_exponentiation\">SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**'</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Bad_super_prop\">SyntaxError: use of super property/member accesses only valid within methods or eval code within methods</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Deprecated_source_map_pragma\">SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/is_not_iterable\">TypeError: 'x' is not iterable</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Unexpected_type\">TypeError: \"x\" is (not) \"y\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_constructor\">TypeError: \"x\" is not a constructor</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Not_a_function\">TypeError: \"x\" is not a function</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/No_non-null_object\">TypeError: \"x\" is not a non-null object</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Read-only\">TypeError: \"x\" is read-only</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/BigInt_not_serializable\">TypeError: BigInt value can't be serialized in JSON</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Builtin_ctor_no_new\">TypeError: calling a builtin X constructor without new is forbidden</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Get_set_missing_private\">TypeError: can't access/set private field or method: object is not the right class</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_assign_to_property\">TypeError: can't assign to property \"x\" on \"y\": not an object</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_convert_BigInt_to_number\">TypeError: can't convert BigInt to number</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_convert_x_to_BigInt\">TypeError: can't convert x to BigInt</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_define_property_object_not_extensible\">TypeError: can't define property \"x\": \"obj\" is not extensible</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Non_configurable_array_element\">TypeError: can't delete non-configurable array element</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_redefine_property\">TypeError: can't redefine non-configurable property \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_set_prototype\">TypeError: can't set prototype of this object</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cyclic_prototype\">TypeError: can't set prototype: it would cause a prototype chain cycle</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/in_operator_no_object\">TypeError: invalid 'in' operand \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Class_ctor_no_new\">TypeError: class constructors must be invoked with 'new'</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value\">TypeError: cyclic object value</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_derived_return\">TypeError: derived class constructor returned invalid value x</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Private_setter_only\">TypeError: getting private setter-only property</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Private_double_initialization\">TypeError: Initializing an object twice is an error with private fields/methods</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/invalid_right_hand_side_instanceof_operand\">TypeError: invalid 'instanceof' operand 'x'</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Array_sort_argument\">TypeError: invalid Array.prototype.sort argument</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Invalid_const_assignment\">TypeError: invalid assignment to const \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Constructor_cant_be_used_directly\">TypeError: Iterator/AsyncIterator constructor can't be used directly</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Requires_global_RegExp\">TypeError: matchAll/replaceAll must be called with a global RegExp</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/More_arguments_needed\">TypeError: More arguments needed</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/No_properties\">TypeError: \"x\" has no properties</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Cant_delete\">TypeError: property \"x\" is non-configurable and can't be deleted</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Reduce_of_empty_array_with_no_initial_value\">TypeError: Reduce of empty array with no initial value</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Getter_only\">TypeError: setting getter-only property \"x\"</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Key_not_weakly_held\">TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Called_on_incompatible_type\">X.prototype.y called on incompatible type</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Malformed_URI\">URIError: malformed URI sequence</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Already_has_pragma\">Warning: -file- is being assigned a //# sourceMappingURL, but already has one</a></li><li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Errors/Stmt_after_return\">Warning: unreachable code after return statement</a></li></ol>\n </details>\n </li>\n <li class=\"toggle\">\n <details>\n <summary>更多</summary>\n <ol>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview\">JavaScript 技术概要</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Lexical_grammar\">词法文法</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Iteration_protocols\">迭代协议</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Strict_mode\">严格模式</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Template_literals\">模板字符串</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Trailing_commas\">尾后逗号</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features\">已废弃的特性</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><strong>JavaScript</strong>（<strong>JS</strong>）是一种具有<a href=\"/zh-CN/docs/Glossary/First-class_Function\">函数优先</a>特性的轻量级、解释型或者说<a href=\"https://zh.wikipedia.org/wiki/%E5%8D%B3%E6%99%82%E7%B7%A8%E8%AD%AF\" class=\"external\" target=\"_blank\">即时编译型</a>的编程语言。虽然作为 Web 页面中的脚本语言被人所熟知，但是它也被用到了很多<a href=\"https://zh.wikipedia.org/wiki/JavaScript#%E5%85%B6%E4%BB%96\" class=\"external\" target=\"_blank\">非浏览器环境</a>中，例如 <a href=\"/zh-CN/docs/Glossary/Node.js\">Node.js</a>、<a href=\"https://couchdb.apache.org\" class=\"external\" target=\"_blank\">Apache CouchDB</a>、<a href=\"https://opensource.adobe.com/dc-acrobat-sdk-docs/acrobatsdk/\" class=\"external\" target=\"_blank\">Adobe Acrobat</a> 等。进一步说，JavaScript 是一种<a href=\"/zh-CN/docs/Glossary/Prototype-based_programming\">基于原型</a>、多范式、<a href=\"/zh-CN/docs/Glossary/Thread\">单线程</a>的<a href=\"/zh-CN/docs/Glossary/Dynamic_typing\">动态</a>语言，并且支持面向对象、命令式和声明式（如函数式编程）风格。</p>\n<p>JavaScript 的动态特性包括运行时对象的构造、变量参数列表、函数变量、动态脚本创建（通过 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/eval\"><code>eval</code></a>）、对象内枚举（通过 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in\"><code>for...in</code></a> 和 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object#%E9%9D%99%E6%80%81%E6%96%B9%E6%B3%95\"><code>Object</code> 工具方法</a>）和源代码恢复（JavaScript 函数会存储其源代码文本，可以使用 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/toString\"><code>toString()</code></a> 进行检索）。</p>\n<p>本部分文档将专注于 JavaScript 语言本身，而不是专注于 Web 页面或其他宿主环境特有的那部分。想要了解 Web 页面特有的 <a href=\"/zh-CN/docs/Glossary/API\">API</a> 信息，请参考 <a href=\"/zh-CN/docs/Web/API\">Web API</a> 以及 <a href=\"/zh-CN/docs/Glossary/DOM\">DOM</a>。</p>\n<p>JavaScript 标准是 <a href=\"https://tc39.es/ecma262/\" class=\"external\" target=\"_blank\">ECMAScript 语言规范</a>（ECMA-262）和 <a href=\"https://tc39.es/ecma402/\" class=\"external\" target=\"_blank\">ECMAScript 国际化 API 规范</a>（ECMA-402）。只要某个浏览器实现了某个特性，我们就会尝试详细记录这个特性。这意味着，当某个 <a href=\"https://github.com/tc39/proposals\" class=\"external\" target=\"_blank\">ECMAScript 新特性的提案</a>在浏览器中实现时，文档和 MDN 文章中的示例可能会使用这些新特性。大多数时候发生在<a href=\"https://tc39.es/process-document/\" class=\"external\" target=\"_blank\">阶段</a> 3 和阶段 4 之间，通常在正式发布之前。</p>\n<p>不要将 JavaScript 与 <a href=\"https://zh.wikipedia.org/wiki/Java\" class=\"external\" target=\"_blank\">Java 编程语言</a>弄混——<strong>JavaScript <em>不是</em>“解释型的 Java”</strong>。“Java”和“JavaScript”都是 Oracle 公司在美国和其他国家注册（或未注册）的商标。然而，这两门编程语言有着非常不同的语法、语义和用途。</p>\n<p>JavaScript 核心语言特性（大部分是纯 <a href=\"/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview\">ECMAScript</a>）的文档包含以下内容：</p>\n<ul>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Guide\">JavaScript 指南</a></li>\n <li><a href=\"/zh-CN/docs/Web/JavaScript/Reference\">JavaScript 参考</a></li>\n</ul>\n<p>有关 JavaScript 规范和相关技术的更多信息，请参阅 <a href=\"/zh-CN/docs/Web/JavaScript/JavaScript_technologies_overview\">JavaScript 技术概述</a>。</p>"}},{"type":"prose","value":{"id":"教程","title":"教程","isH3":false,"content":"<p>借助指南和教程来学习如何用 JavaScript 编程。</p>"}},{"type":"prose","value":{"id":"面向纯新手","title":"面向纯新手","isH3":true,"content":"<p>如果你想学习 JavaScript，却从未接触过 JavaScript 或编程，你可以投入到我们的 <a href=\"/zh-CN/docs/Learn/JavaScript\">JavaScript 主题学习区</a>。下面列出了这部分的所有章节：</p>\n<dl>\n <dt id=\"javascript_第一步\"><a href=\"/zh-CN/docs/Learn/JavaScript/First_steps\">JavaScript 第一步</a></dt>\n <dd>\n <p>回答一些基本问题，比如“JavaScript 是什么？”、“它长什么样子？”、“它可以用来做什么？”等，还谈及如变量、字符串、数字、数组等 JavaScript 关键特性。</p>\n </dd>\n <dt id=\"创建_javascript_代码块\"><a href=\"/zh-CN/docs/Learn/JavaScript/Building_blocks\">创建 JavaScript 代码块</a></dt>\n <dd>\n <p>继续介绍 JavaScript 的关键基本特性，将注意力转向常见的代码块类型，如条件语句、循环、函数、事件等。</p>\n </dd>\n <dt id=\"介绍_javascript_对象\"><a href=\"/zh-CN/docs/Learn/JavaScript/Objects\">介绍 JavaScript 对象</a></dt>\n <dd>\n <p>如果你想进一步提高对语言的了解并编写出更高效的代码，理解 JavaScript 面向对象的本质很重要，因此我们为你准备了这个模块。</p>\n </dd>\n <dt id=\"异步_javascript\"><a href=\"/zh-CN/docs/Learn/JavaScript/Asynchronous\">异步 JavaScript</a></dt>\n <dd>\n <p>探讨异步 JavaScript、为什么它很重要、如何使用它有效地处理潜在的阻塞操作（如从服务器获取资源）。</p>\n </dd>\n <dt id=\"客户端_web_api\"><a href=\"/zh-CN/docs/Learn/JavaScript/Client-side_web_APIs\">客户端 web API</a></dt>\n <dd>\n <p>探讨 API 是什么、如何使用一些开发工作中最常见的 API。</p>\n </dd>\n</dl>"}},{"type":"prose","value":{"id":"javascript_指南","title":"JavaScript 指南","isH3":true,"content":"<dl>\n <dt id=\"javascript_指南_2\"><a href=\"/zh-CN/docs/Web/JavaScript/Guide\">JavaScript 指南</a></dt>\n <dd>\n <p>一份非常详细的 JavaScript 指南，适用于有过 JavaScript 或其他语言编程经验的读者。</p>\n </dd>\n</dl>"}},{"type":"prose","value":{"id":"中级","title":"中级","isH3":true,"content":"<dl>\n <dt id=\"理解客户端_javascript_框架\"><a href=\"/zh-CN/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks\">理解客户端 Javascript 框架</a></dt>\n <dd>\n <p>JavaScript 框架是现代前端 Web 开发必不可少的一部分，为开发者构建可扩展、交互式的 Web 应用程序提供了经过验证的工具。这个模块讨论一些客户端框架如何工作以及如何集成到工具集的基础背景知识，接着是一个讨论现在最流行框架的系列教程。</p>\n </dd>\n <dt id=\"javascript_语言概述\"><a href=\"/zh-CN/docs/Web/JavaScript/Language_overview\">JavaScript 语言概述</a></dt>\n <dd>\n <p>JavaScript 基础语法和语义概述：帮助来自其他编程语言的读者加速学习。</p>\n </dd>\n <dt id=\"javascript_数据结构\"><a href=\"/zh-CN/docs/Web/JavaScript/Data_structures\">JavaScript 数据结构</a></dt>\n <dd>\n <p>JavaScript 数据结构概述。</p>\n </dd>\n <dt id=\"相等比较和相同\"><a href=\"/zh-CN/docs/Web/JavaScript/Equality_comparisons_and_sameness\">相等比较和相同</a></dt>\n <dd>\n <p>JavaScript 提供了三种不同的值比较运算：严格相等运算符 <code>===</code>、非严格相等运算符 <code>==</code>，以及 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/is\"><code>Object.is()</code></a> 方法。</p>\n </dd>\n <dt id=\"属性的可枚举性和所有权\"><a href=\"/zh-CN/docs/Web/JavaScript/Enumerability_and_ownership_of_properties\">属性的可枚举性和所有权</a></dt>\n <dd>\n <p>不同的处理属性的可枚举性和所有权的方法——一个接着一个的访问一组对象属性。</p>\n </dd>\n <dt id=\"闭包\"><a href=\"/zh-CN/docs/Web/JavaScript/Closures\">闭包</a></dt>\n <dd>\n <p>闭包是由函数及其声明所在的词法环境结合而成。</p>\n </dd>\n</dl>"}},{"type":"prose","value":{"id":"高级","title":"高级","isH3":true,"content":"<dl>\n <dt id=\"继承与原型链\"><a href=\"/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain\">继承与原型链</a></dt>\n <dd>\n <p>解释被广泛误解与低估的基于原型的继承。</p>\n </dd>\n <dt id=\"内存管理\"><a href=\"/zh-CN/docs/Web/JavaScript/Memory_management\">内存管理</a></dt>\n <dd>\n <p>JavaScript 的内存生命周期和垃圾回收。</p>\n </dd>\n <dt id=\"事件循环\"><a href=\"/zh-CN/docs/Web/JavaScript/Event_loop\">事件循环</a></dt>\n <dd>\n <p>JavaScript 拥有基于“事件循环”的运行时模型。</p>\n </dd>\n</dl>"}},{"type":"prose","value":{"id":"参考","title":"参考","isH3":false,"content":"<p>浏览完整的 <a href=\"/zh-CN/docs/Web/JavaScript/Reference\">JavaScript 参考</a>文档。</p>\n<dl>\n <dt id=\"标准对象\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects\">标准对象</a></dt>\n <dd>\n <p>了解 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array\"><code>Array</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Boolean\"><code>Boolean</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Date\"><code>Date</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Error\"><code>Error</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function\"><code>Function</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON\"><code>JSON</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Math\"><code>Math</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Number\"><code>Number</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object\"><code>Object</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp\"><code>RegExp</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String\"><code>String</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Map\"><code>Map</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Set\"><code>Set</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakMap\"><code>WeakMap</code></a> 、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/WeakSet\"><code>WeakSet</code></a> 等标准内置对象。</p>\n </dd>\n <dt id=\"表达式和运算符\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators\">表达式和运算符</a></dt>\n <dd>\n <p>学习运算符 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/instanceof\"><code>instanceof</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof\"><code>typeof</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/new\"><code>new</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/this\"><code>this</code></a>，<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Operators/Operator_precedence\">运算符优先级</a>，以及其他运算符的行为。</p>\n </dd>\n <dt id=\"语句和声明\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements\">语句和声明</a></dt>\n <dd>\n <p>学习 <a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/do...while\"><code>do-while</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for...in\"><code>for-in</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/for...of\"><code>for-of</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/try...catch\"><code>try-catch</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/let\"><code>let</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/var\"><code>var</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/const\"><code>const</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/if...else\"><code>if-else</code></a>、<a href=\"/zh-CN/docs/Web/JavaScript/Reference/Statements/switch\"><code>switch</code></a> 以及其他语句和关键字的作用。</p>\n </dd>\n <dt id=\"函数\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Functions\">函数</a></dt>\n <dd>\n <p>学习如何使用 JavaScript 函数开发应用。</p>\n </dd>\n <dt id=\"类\"><a href=\"/zh-CN/docs/Web/JavaScript/Reference/Classes\">类</a></dt>\n <dd>\n <p>JavaScript 类是最适合面向对象编程的方式。</p>\n </dd>\n</dl>"}}],"toc":[{"text":"教程","id":"教程"},{"text":"参考","id":"参考"}],"summary":"JavaScript（JS）是一种具有函数优先特性的轻量级、解释型或者说即时编译型的编程语言。虽然作为 Web 页面中的脚本语言被人所熟知，但是它也被用到了很多非浏览器环境中，例如 Node.js、Apache CouchDB、Adobe Acrobat 等。进一步说，JavaScript 是一种基于原型、多范式、单线程的动态语言，并且支持面向对象、命令式和声明式（如函数式编程）风格。","popularity":0.0626,"modified":"2024-11-10T06:44:38.000Z","other_translations":[{"locale":"de","title":"JavaScript","native":"Deutsch"},{"locale":"en-US","title":"JavaScript","native":"English (US)"},{"locale":"es","title":"JavaScript","native":"Español"},{"locale":"fr","title":"JavaScript","native":"Français"},{"locale":"ja","title":"JavaScript","native":"日本語"},{"locale":"ko","title":"JavaScript","native":"한국어"},{"locale":"pt-BR","title":"JavaScript","native":"Português (do Brasil)"},{"locale":"ru","title":"JavaScript","native":"Русский"},{"locale":"zh-TW","title":"JavaScript","native":"正體中文 (繁體)"}],"pageType":"unknown","source":{"folder":"zh-cn/web/javascript","github_url":"https://github.com/mdn/translated-content/blob/main/files/zh-cn/web/javascript/index.md","last_commit_url":"https://github.com/mdn/translated-content/commit/ae76d18526fe5f81efb666892ec9d88cdd7eb5c4","filename":"index.md"},"short_title":"JavaScript","parents":[{"uri":"/zh-CN/docs/Web","title":"面向开发者的 Web 技术"},{"uri":"/zh-CN/docs/Web/JavaScript","title":"JavaScript"}],"pageTitle":"JavaScript | MDN","noIndexing":false}}</script></body></html>