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mw-first-heading"><span class="mw-page-title-main">Short-circuit evaluation</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. 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href="https://de.wikipedia.org/wiki/Kurzschlussauswertung" title="Kurzschlussauswertung – German" lang="de" hreflang="de" data-title="Kurzschlussauswertung" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Evaluaci%C3%B3n_de_cortocircuito" title="Evaluación de cortocircuito – Spanish" lang="es" hreflang="es" data-title="Evaluación de cortocircuito" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%A7%D8%B1%D8%B2%DB%8C%D8%A7%D8%A8%DB%8C_%D8%A7%D8%AA%D8%B5%D8%A7%D9%84_%DA%A9%D9%88%D8%AA%D8%A7%D9%87" title="ارزیابی اتصال کوتاه – Persian" lang="fa" hreflang="fa" data-title="ارزیابی اتصال کوتاه" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Valutazione_a_corto_circuito" title="Valutazione a corto circuito – Italian" lang="it" hreflang="it" data-title="Valutazione a corto circuito" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E7%9F%AD%E7%B5%A1%E8%A9%95%E4%BE%A1" title="短絡評価 – Japanese" lang="ja" hreflang="ja" data-title="短絡評価" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Avalia%C3%A7%C3%A3o_de_curto-circuito" title="Avaliação de curto-circuito – Portuguese" lang="pt" hreflang="pt" 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.sidebar-title-with-pretitle{background:transparent!important}html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media print{body.ns-0 .mw-parser-output .sidebar{display:none!important}}</style><table class="sidebar nomobile nowraplinks"><tbody><tr><th class="sidebar-title"><a href="/wiki/Evaluation_strategy" title="Evaluation strategy">Evaluation strategies</a></th></tr><tr><td class="sidebar-content" style="text-align: left"> <ul><li><a href="/wiki/Lazy_evaluation" title="Lazy evaluation">Lazy evaluation</a></li> <li><a href="/wiki/Partial_evaluation" title="Partial evaluation">Partial evaluation</a></li> <li><a href="/wiki/Remote_evaluation" title="Remote evaluation">Remote evaluation</a></li> <li><a class="mw-selflink selflink">Short-circuit evaluation</a></li></ul></td> </tr><tr><td class="sidebar-navbar"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Evaluation_strategy" title="Template:Evaluation strategy"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Evaluation_strategy" title="Template talk:Evaluation strategy"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Evaluation_strategy" title="Special:EditPage/Template:Evaluation strategy"><abbr title="Edit this template">e</abbr></a></li></ul></div></td></tr></tbody></table> <p><b>Short-circuit evaluation</b>, <b>minimal evaluation</b>, or <b>McCarthy evaluation</b> (after <a href="/wiki/John_McCarthy_(computer_scientist)" title="John McCarthy (computer scientist)">John McCarthy</a>) is the semantics of some <a href="/wiki/Logical_connective" title="Logical connective">Boolean operators</a> in some <a href="/wiki/Programming_language" title="Programming language">programming languages</a> in which the second argument is executed or evaluated only if the first argument does not suffice to determine the value of the expression: when the first argument of the <code>AND</code> function evaluates to <code>false</code>, the overall value must be <code>false</code>; and when the first argument of the <code>OR</code> function evaluates to <code>true</code>, the overall value must be <code>true</code>. </p><p>In programming languages with <a href="/wiki/Lazy_evaluation" title="Lazy evaluation">lazy evaluation</a> (<a href="/wiki/Lisp_(programming_language)" title="Lisp (programming language)">Lisp</a>, <a href="/wiki/Perl" title="Perl">Perl</a>, <a href="/wiki/Haskell" title="Haskell">Haskell</a>), the usual <a href="/wiki/Boolean_expression" title="Boolean expression">Boolean operators</a> short-circuit. In others (<a href="/wiki/Ada_(programming_language)" title="Ada (programming language)">Ada</a>, <a href="/wiki/Java_(programming_language)" title="Java (programming language)">Java</a>, <a href="/wiki/Delphi_(software)" title="Delphi (software)">Delphi</a>), both short-circuit and standard Boolean operators are available. For some Boolean operations, like <i><a href="/wiki/Exclusive_or" title="Exclusive or">exclusive or</a></i> (XOR), it is impossible to short-circuit, because both operands are always needed to determine a result. </p><p>Short-circuit operators are, in effect, <a href="/wiki/Control_structure" class="mw-redirect" title="Control structure">control structures</a> rather than simple arithmetic operators, as they are not <a href="/wiki/Strict_function" title="Strict function">strict</a>. In <a href="/wiki/Imperative_language" class="mw-redirect" title="Imperative language">imperative language</a> terms (notably <a href="/wiki/C_(programming_language)" title="C (programming language)">C</a> and <a href="/wiki/C%2B%2B" title="C++">C++</a>), where side effects are important, short-circuit operators introduce a <a href="/wiki/Sequence_point" title="Sequence point">sequence point</a>: they completely evaluate the first argument, including any <a href="/wiki/Side_effect_(computer_science)" title="Side effect (computer science)">side effects</a>, before (optionally) processing the second argument. <a href="/wiki/ALGOL_68" title="ALGOL 68">ALGOL 68</a> used <i>proceduring</i> to achieve <i>user-defined</i> short-circuit operators and procedures. </p><p>The use of short-circuit operators has been criticized as problematic: </p> <style data-mw-deduplicate="TemplateStyles:r1244412712">.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}}</style><blockquote class="templatequote"><p>The conditional connectives — "<u>cand</u>" and "<u>cor</u>" for short — are ... less innocent than they might seem at first sight. For instance, <u>cor</u> does not distribute over <u>cand</u>: compare </p><dl><dd>(A <u>cand</u> B) <u>cor</u> C <i>with</i> (A <u>cor</u> C) <u>cand</u> (B <u>cor</u> C);</dd></dl><p> in the case ¬A ∧ C , the second expression requires B to be defined, the first one does not. Because the conditional connectives thus complicate the formal reasoning about programs, they are better avoided.</p><div class="templatequotecite">— <cite><a href="/wiki/Edsger_W._Dijkstra" title="Edsger W. Dijkstra">Edsger W. Dijkstra</a><sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></cite></div></blockquote> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Definition">Definition</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=1" title="Edit section: Definition"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In any programming language that implements short-circuit evaluation, the expression <code><i>x</i> and <i>y</i></code> is equivalent to the <a href="/wiki/Conditional_(programming)" class="mw-redirect" title="Conditional (programming)">conditional expression</a> <code>if <i>x</i> then <i>y</i> else <i>x</i></code>, and the expression <code><i>x</i> or <i>y</i></code> is equivalent to <code>if <i>x</i> then <i>x</i> else <i>y</i></code>. In either case, <i>x</i> is only evaluated once. </p><p>The generalized definition above accommodates loosely typed languages that have more than the two <a href="/wiki/Truth-value" class="mw-redirect" title="Truth-value">truth-values</a> <code>True</code> and <code>False</code>, where short-circuit operators may return the last evaluated subexpression. This is called "last value" in the table below. For a strictly-typed language, the expression is simplified to <code>if <i>x</i> then <i>y</i> else <b>false</b></code> and <code>if <i>x</i> then <b>true</b> else <i>y</i></code> respectively for the boolean case. </p> <div class="mw-heading mw-heading3"><h3 id="Precedence">Precedence</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=2" title="Edit section: Precedence"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Although <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">AND</code> takes <a href="/wiki/Operator_precedence" class="mw-redirect" title="Operator precedence">precedence</a> over <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">OR</code> in many languages, this is not a universal property of short-circuit evaluation. An example of the two operators taking the same precedence and being <a href="/wiki/Left-associative" class="mw-redirect" title="Left-associative">left-associative</a> with each other is <a href="/wiki/POSIX_shell" class="mw-redirect" title="POSIX shell">POSIX shell</a>'s command-list syntax.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Location: §2.9.3">: §2.9.3 </span></sup> </p><p>The following simple left-to-right evaluator enforces a precedence of <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">AND</code> over <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">OR</code> by a <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">continue</code>: </p> <pre><b>function</b> short-circuit-eval (<i>operators</i>, <i>values</i>) <b>let</b> <i>result</i> := True <b>for each</b> (<i>op</i>, <i>val</i>) in (<i>operators</i>, <i>values</i>): <b>if</b> <i>op</i> = "AND" && <i>result</i> = False <b>continue</b> <b>else if</b> <i>op</i> = "OR" && <i>result</i> = True <b>return</b> <i>result</i> <b>else</b> <i>result</i> := <i>val</i> <b>return</b> <i>result</i> </pre> <div class="mw-heading mw-heading3"><h3 id="Formalization">Formalization</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=3" title="Edit section: Formalization"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Short-circuit logic, with or without side-effects, have been formalized based on <a href="/wiki/Hoare_logic#Conditional_rule" title="Hoare logic">Hoare's conditional</a>. A result is that non-short-circuiting operators can be defined out of short-circuit logic to have the same sequence of evaluation.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Support_in_common_programming_and_scripting_languages">Support in common programming and scripting languages</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=4" title="Edit section: Support in common programming and scripting languages"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>As you look at the table below, keep in mind that bitwise operators often do not behave exactly like logical operators, even if both arguments are of <code>0</code>, <code>1</code> or Boolean type. </p><p>Examples: </p> <ul><li>In JavaScript, each of the following 3 expressions evaluates to <code>false</code>:<br /><code>(true & true) === (true && true)</code>,<br /><code>(false | false) === (false || false)</code>,<br /><code>(1 & 2) === (1 && 2)</code>.</li> <li>In PHP, each of the following 3 expressions evaluates to <code>false</code>:<br /><code>(true & true) === (true && true)</code>,<br /><code>(0 | 0) === (0 || 0)</code>,<br /><code>(1 & 2) === (1 && 2)</code>.</li></ul> <table class="wikitable"> <caption>Boolean operators in various languages </caption> <tbody><tr> <th>Language</th> <th><a href="/wiki/Eager_evaluation" class="mw-redirect" title="Eager evaluation">Eager</a> operators</th> <th>Short-circuit operators</th> <th>Result type </th></tr> <tr> <td>Advanced Business Application Programming (<a href="/wiki/ABAP" title="ABAP">ABAP</a>) </td> <td><i>none</i> </td> <td><code>and</code>, <code>or</code> </td> <td>Boolean<sup id="cite_ref-abap-apl_4-0" class="reference"><a href="#cite_note-abap-apl-4"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><a href="/wiki/Ada_(programming_language)" title="Ada (programming language)">Ada</a> </td> <td><code>and</code>, <code>or</code> </td> <td><code>and then</code>, <code>or else</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/ALGOL_68" title="ALGOL 68">ALGOL 68</a> </td> <td>and, &, ∧ ; or, ∨ </td> <td style="background: #FED; color:black; vertical-align: middle; text-align: center;" class="depends table-depends">andf , orf <i>(both user defined)</i> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/APL_(programming_language)" title="APL (programming language)">APL</a> </td> <td><code>∧</code>, <code>∨</code>, <code>⍲</code> (nand), <code>⍱</code> (nor), etc. </td> <td><code>:AndIf</code>, <code>:OrIf</code> </td> <td>Boolean<sup id="cite_ref-abap-apl_4-1" class="reference"><a href="#cite_note-abap-apl-4"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><a href="/wiki/Awk" class="mw-redirect" title="Awk">awk</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Bash_(Unix_shell)" title="Bash (Unix shell)">Bash</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/C_(programming_language)" title="C (programming language)">C</a>, <a href="/wiki/Objective-C" title="Objective-C">Objective-C</a> </td> <td><code>&</code>, <code>|</code><sup id="cite_ref-bitwise_c_6-0" class="reference"><a href="#cite_note-bitwise_c-6"><span class="cite-bracket">[</span>b<span class="cite-bracket">]</span></a></sup> </td> <td><code>&&</code>, <code>||</code>, <code>?</code><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </td> <td>int (<code>&</code>, <code>|</code>, <code>&&</code>,<code>||</code>), opnd-dependent (<code>?</code>) </td></tr> <tr> <td><a href="/wiki/C%2B%2B" title="C++">C++</a><sup id="cite_ref-cpp_8-0" class="reference"><a href="#cite_note-cpp-8"><span class="cite-bracket">[</span>c<span class="cite-bracket">]</span></a></sup> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code>, <code>?</code><sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean (<code>&&</code>,<code>||</code>), opnd-dependent (<code>?</code>) </td></tr> <tr> <td><a href="/wiki/C_Sharp_(programming_language)" title="C Sharp (programming language)">C#</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>||</code>, <code>?</code>, <code>??</code> </td> <td>Boolean (<code>&&</code>,<code>||</code>), opnd-dependent (<code>?</code>, <code>??</code>) </td></tr> <tr> <td><a href="/wiki/ColdFusion_Markup_Language" title="ColdFusion Markup Language">ColdFusion Markup Language</a> (CFML) </td> <td><i>none</i> </td> <td><code>AND</code>, <code>OR</code>, <code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/D_(programming_language)" title="D (programming language)">D</a><sup id="cite_ref-d_10-0" class="reference"><a href="#cite_note-d-10"><span class="cite-bracket">[</span>d<span class="cite-bracket">]</span></a></sup> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>||</code>, <code>?</code> </td> <td>Boolean (<code>&&</code>,<code>||</code>), opnd-dependent (<code>?</code>) </td></tr> <tr> <td><a href="/wiki/Eiffel_(programming_language)" title="Eiffel (programming language)">Eiffel</a> </td> <td><code>and</code>, <code>or</code> </td> <td><code>and then</code>, <code>or else</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Erlang_(programming_language)" title="Erlang (programming language)">Erlang</a> </td> <td><code>and</code>, <code>or</code> </td> <td><code>andalso</code>, <code>orelse</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Fortran" title="Fortran">Fortran</a><sup id="cite_ref-fortran_11-0" class="reference"><a href="#cite_note-fortran-11"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup> </td> <td><code>.and.</code>, <code>.or.</code> </td> <td><code>.and.</code>, <code>.or.</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Go_(programming_language)" title="Go (programming language)">Go</a>, <a href="/wiki/Haskell_(programming_language)" class="mw-redirect" title="Haskell (programming language)">Haskell</a>, <a href="/wiki/OCaml" title="OCaml">OCaml</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Java_(programming_language)" title="Java (programming language)">Java</a>, <a href="/wiki/MATLAB" title="MATLAB">MATLAB</a>, <a href="/wiki/R_(programming_language)" title="R (programming language)">R</a>, <a href="/wiki/Swift_(programming_language)" title="Swift (programming language)">Swift</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/JavaScript" title="JavaScript">JavaScript</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>&&=</code>, <code>||</code>, <code>||=</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/Julia_(programming_language)" title="Julia (programming language)">Julia</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/Lasso_(programming_language)" title="Lasso (programming language)">Lasso</a> </td> <td><i>none</i> </td> <td><code>and</code>, <code>or</code>, <code>&&</code>, <code>||</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/Kotlin_(programming_language)" title="Kotlin (programming language)">Kotlin</a> </td> <td><code>and</code>, <code>or</code> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Lisp_(programming_language)" title="Lisp (programming language)">Lisp</a>, <a href="/wiki/Lua_(programming_language)" title="Lua (programming language)">Lua</a>, <a href="/wiki/Scheme_(programming_language)" title="Scheme (programming language)">Scheme</a> </td> <td><i>none</i> </td> <td><code>and</code>, <code>or</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/MUMPS" title="MUMPS">MUMPS</a> (M) </td> <td><code>&</code>, <code>!</code> </td> <td><i>none</i> </td> <td>Numeric </td></tr> <tr> <td><a href="/wiki/Modula-2" title="Modula-2">Modula-2</a> </td> <td><i>none</i> </td> <td><code>AND</code>, <code>OR</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Oberon_(programming_language)" title="Oberon (programming language)">Oberon</a> </td> <td><i>none</i> </td> <td><code>&</code>, <code>OR</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/OCaml" title="OCaml">OCaml</a> </td> <td><code>land</code>, <code>lor</code><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </td> <td><code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Pascal_(programming_language)" title="Pascal (programming language)">Pascal</a> </td> <td><code>and</code>, <code>or</code><sup id="cite_ref-pascal-1_13-0" class="reference"><a href="#cite_note-pascal-1-13"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-delphi_14-0" class="reference"><a href="#cite_note-delphi-14"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td><code>and_then</code>, <code>or_else</code><sup id="cite_ref-delphi_14-1" class="reference"><a href="#cite_note-delphi-14"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Perl" title="Perl">Perl</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>and</code>, <code>||</code>, <code>or</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/PHP" title="PHP">PHP</a> </td> <td><i>none</i> </td> <td><code>&&</code>, <code>and</code>, <code>||</code>, <code>or</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/POSIX_shell" class="mw-redirect" title="POSIX shell">POSIX shell</a> (command list) </td> <td><i>none</i> </td> <td><code>&&</code>, <code>||</code> </td> <td>Last value (exit) </td></tr> <tr> <td><a href="/wiki/PowerShell" title="PowerShell">PowerShell</a> Scripting Language </td> <td><i>none</i> </td> <td><code>-and</code>, <code>-or</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Python_(programming_language)" title="Python (programming language)">Python</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>and</code>, <code>or</code> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/Ruby_(programming_language)" title="Ruby (programming language)">Ruby</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>and</code>, <code>||</code>, <code>or</code><sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </td> <td>Last value </td></tr> <tr> <td><a href="/wiki/Rust_(programming_language)" title="Rust (programming language)">Rust</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>&&</code>, <code>||</code><sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Smalltalk" title="Smalltalk">Smalltalk</a> </td> <td><code>&</code>, <code>|</code> </td> <td><code>and:</code>, <code>or:</code><sup id="cite_ref-smalltalk_17-0" class="reference"><a href="#cite_note-smalltalk-17"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Standard_ML" title="Standard ML">Standard ML</a> </td> <td style="background: var(--background-color-interactive, #EEE); color: var(--color-base, black); vertical-align: middle; white-space: nowrap; text-align: center;" class="table-Unknown">Unknown </td> <td><code>andalso</code>, <code>orelse</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/TTCN-3" title="TTCN-3">TTCN-3</a> </td> <td><i>none</i> </td> <td><code>and</code>, <code>or</code><sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean </td></tr> <tr> <td>Beckhoff TwinCAT® (<a href="/wiki/IEC_61131-3" title="IEC 61131-3">IEC 61131-3</a>)<sup id="cite_ref-twincat_19-0" class="reference"><a href="#cite_note-twincat-19"><span class="cite-bracket">[</span>i<span class="cite-bracket">]</span></a></sup> </td> <td><code>AND</code>, <code>OR</code> </td> <td><code>AND_THEN</code>,<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> <code>OR_ELSE</code><sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Visual_Basic_.NET" class="mw-redirect" title="Visual Basic .NET">Visual Basic .NET</a> </td> <td><code>And</code>, <code>Or</code> </td> <td><code>AndAlso</code>, <code>OrElse</code> </td> <td>Boolean </td></tr> <tr> <td><a href="/wiki/Visual_Basic" title="Visual Basic">Visual Basic</a>, <a href="/wiki/Visual_Basic_for_Applications" title="Visual Basic for Applications">Visual Basic for Applications</a> (VBA) </td> <td><code>And</code>, <code>Or</code> </td> <td><code>Select Case</code><sup id="cite_ref-basic_22-0" class="reference"><a href="#cite_note-basic-22"><span class="cite-bracket">[</span>j<span class="cite-bracket">]</span></a></sup> </td> <td>Numeric </td></tr> <tr> <td><a href="/wiki/Wolfram_Language" title="Wolfram Language">Wolfram Language</a> </td> <td><code>And @@ {...}</code>, <code>Or @@ {...}</code> </td> <td><code>And</code>, <code>Or</code>, <code>&&</code>, <code>||</code> </td> <td>Boolean </td></tr> <tr> <td>ZTT </td> <td><code>&</code>, <code>|</code> </td> <td><i>none</i> </td> <td>Boolean </td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-alpha"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-abap-apl-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-abap-apl_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-abap-apl_4-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">ABAP and APL have no distinct boolean type.</span> </li> <li id="cite_note-bitwise_c-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-bitwise_c_6-0">^</a></b></span> <span class="reference-text">The bitwise operators behave like boolean operators when both arguments are of type <code>bool</code> or take only the values <code>0</code> or <code>1</code>.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup></span> </li> <li id="cite_note-cpp-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-cpp_8-0">^</a></b></span> <span class="reference-text">When <a href="/wiki/Operator_overloading" title="Operator overloading">overloaded</a>, the operators <code>&&</code> and <code>||</code> are eager and can return any type.</span> </li> <li id="cite_note-d-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-d_10-0">^</a></b></span> <span class="reference-text">This only applies to runtime-evaluated expressions, <code>static if</code> and <code>static assert</code>. Expressions in static initializers or manifest constants use eager evaluation.</span> </li> <li id="cite_note-fortran-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-fortran_11-0">^</a></b></span> <span class="reference-text">Fortran operators are neither short-circuit nor eager: the language specification allows the <a href="/wiki/Compiler" title="Compiler">compiler</a> to select the method for optimization.</span> </li> <li id="cite_note-pascal-1-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-pascal-1_13-0">^</a></b></span> <span class="reference-text"><a href="/wiki/Pascal_(programming_language)#ISO/IEC_10206:1990_Extended_Pascal" title="Pascal (programming language)">ISO/IEC 10206:1990 Extended Pascal</a> allows, but does not require, short-circuiting.</span> </li> <li id="cite_note-delphi-14"><span class="mw-cite-backlink">^ <a href="#cite_ref-delphi_14-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-delphi_14-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a href="/wiki/Delphi_(software)" title="Delphi (software)">Delphi</a> and <a href="/wiki/Free_Pascal" title="Free Pascal">Free Pascal</a> default to short circuit evaluation. This may be changed by <a href="/wiki/Compiler" title="Compiler">compiler</a> options but does not seem to be used widely.</span> </li> <li id="cite_note-smalltalk-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-smalltalk_17-0">^</a></b></span> <span class="reference-text">Smalltalk uses short-circuit semantics as long as the argument to <code>and:</code> is a block (e.g., <code>false and: [Transcript show: 'Wont see me']</code>).</span> </li> <li id="cite_note-twincat-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-twincat_19-0">^</a></b></span> <span class="reference-text">The norm <a href="/wiki/IEC_61131-3" title="IEC 61131-3">IEC 61131-3</a> doesn't actually define if <code>AND</code> and <code>OR</code> use short-circuit evaluation and it doesn't define the operators <code>AND_THEN</code> and <code>OR_ELSE</code>. The entries in the table show how it works for Beckhoff TwinCAT®.</span> </li> <li id="cite_note-basic-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-basic_22-0">^</a></b></span> <span class="reference-text"><a href="/wiki/BASIC" title="BASIC">BASIC</a> languages that supported CASE statements did so by using the conditional evaluation system, rather than as jump tables limited to fixed labels.</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="Common_use">Common use</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=5" title="Edit section: Common use"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Avoiding_undesired_side_effects_of_the_second_argument">Avoiding undesired side effects of the second argument</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=6" title="Edit section: Avoiding undesired side effects of the second argument"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Usual example, using a <a href="/wiki/C_(programming_language)" title="C (programming language)">C-based</a> language: </p> <div class="mw-highlight mw-highlight-lang-c mw-content-ltr" dir="ltr"><pre><span></span><span class="kt">int</span><span class="w"> </span><span class="n">denom</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span> <span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">denom</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="n">denom</span><span class="p">)</span> <span class="p">{</span> <span class="w"> </span><span class="p">...</span><span class="w"> </span><span class="c1">// ensures that calculating num/denom never results in divide-by-zero error </span> <span class="p">}</span> </pre></div> <p>Consider the following example: </p> <div class="mw-highlight mw-highlight-lang-c mw-content-ltr" dir="ltr"><pre><span></span><span class="kt">int</span><span class="w"> </span><span class="n">a</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span> <span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">a</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">myfunc</span><span class="p">(</span><span class="n">b</span><span class="p">))</span> <span class="p">{</span> <span class="w"> </span><span class="n">do_something</span><span class="p">();</span> <span class="p">}</span> </pre></div> <p>In this example, short-circuit evaluation guarantees that <code>myfunc(b)</code> is never called. This is because <code>a != 0</code> evaluates to <i>false</i>. This feature permits two useful programming constructs. </p> <ol><li>If the first sub-expression checks whether an expensive computation is needed and the check evaluates to <i>false</i>, one can eliminate expensive computation in the second argument.</li> <li>It permits a construct where the first expression guarantees a condition without which the second expression may cause a <a href="/wiki/Run-time_error" class="mw-redirect" title="Run-time error">run-time error</a>.</li></ol> <p>Both are illustrated in the following C snippet where minimal evaluation prevents both null pointer dereference and excess memory fetches: </p> <div class="mw-highlight mw-highlight-lang-cpp mw-content-ltr" dir="ltr"><pre><span></span><span class="kt">bool</span><span class="w"> </span><span class="nf">is_first_char_valid_alpha_unsafe</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">p</span><span class="p">)</span> <span class="p">{</span> <span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">isalpha</span><span class="p">(</span><span class="n">p</span><span class="p">[</span><span class="mi">0</span><span class="p">]);</span><span class="w"> </span><span class="c1">// SEGFAULT highly possible with p == NULL</span> <span class="p">}</span> <span class="kt">bool</span><span class="w"> </span><span class="nf">is_first_char_valid_alpha</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">p</span><span class="p">)</span> <span class="p">{</span> <span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">p</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">isalpha</span><span class="p">(</span><span class="n">p</span><span class="p">[</span><span class="mi">0</span><span class="p">]);</span><span class="w"> </span><span class="c1">// 1) no unneeded isalpha() execution with p == NULL, 2) no SEGFAULT risk</span> <span class="p">}</span> </pre></div> <div class="mw-heading mw-heading3"><h3 id="Idiomatic_conditional_construct">Idiomatic conditional construct</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=7" title="Edit section: Idiomatic conditional construct"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Since minimal evaluation is part of an operator's semantic definition and not an optional <a href="/wiki/Compiler_optimization" class="mw-redirect" title="Compiler optimization">optimization</a>, a number of coding idioms rely on it as a succinct conditional construct. Examples include: </p><p><a href="/wiki/Perl" title="Perl">Perl</a> idioms: </p> <div class="mw-highlight mw-highlight-lang-perl mw-content-ltr" dir="ltr"><pre><span></span><span class="n">some_condition</span><span class="w"> </span><span class="ow">or</span><span class="w"> </span><span class="nb">die</span><span class="p">;</span><span class="w"> </span><span class="c1"># Abort execution if some_condition is false</span> <span class="n">some_condition</span><span class="w"> </span><span class="ow">and</span><span class="w"> </span><span class="nb">die</span><span class="p">;</span><span class="w"> </span><span class="c1"># Abort execution if some_condition is true</span> </pre></div> <p><a href="/wiki/POSIX_shell" class="mw-redirect" title="POSIX shell">POSIX shell</a> idioms:<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-highlight mw-highlight-lang-bash mw-content-ltr" dir="ltr"><pre><span></span>modprobe<span class="w"> </span>-q<span class="w"> </span>some_module<span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="nb">echo</span><span class="w"> </span><span class="s2">"some_module installed"</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="nb">echo</span><span class="w"> </span><span class="s2">"some_module not installed"</span> </pre></div> <p>This idiom presumes that <code>echo</code> cannot fail. </p> <div class="mw-heading mw-heading2"><h2 id="Possible_problems">Possible problems</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=8" title="Edit section: Possible problems"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Untested_second_condition_leads_to_unperformed_side_effect">Untested second condition leads to unperformed side effect</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=9" title="Edit section: Untested second condition leads to unperformed side effect"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Despite these benefits, minimal evaluation may cause problems for programmers who do not realize (or forget) it is happening. For example, in the code </p> <div class="mw-highlight mw-highlight-lang-c mw-content-ltr" dir="ltr"><pre><span></span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">expressionA</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">myfunc</span><span class="p">(</span><span class="n">b</span><span class="p">))</span><span class="w"> </span><span class="p">{</span> <span class="w"> </span><span class="n">do_something</span><span class="p">();</span> <span class="p">}</span> </pre></div> <p>if <code>myfunc(b)</code> is supposed to perform some required operation regardless of whether <code>do_something()</code> is executed, such as allocating system resources, and <code>expressionA</code> evaluates as false, then <code>myfunc(b)</code> will not execute, which could cause problems. Some programming languages, such as <a href="/wiki/Java_(programming_language)" title="Java (programming language)">Java</a>, have two operators, one that employs minimal evaluation and one that does not, to avoid this problem. </p><p>Problems with unperformed side effect statements can be easily solved with proper programming style, i.e., not using side effects in boolean statements, as using values with side effects in evaluations tends to generally make the code opaque and error-prone.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Reduced_efficiency_due_to_constraining_optimizations">Reduced efficiency due to constraining optimizations</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=10" title="Edit section: Reduced efficiency due to constraining optimizations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Short-circuiting can lead to errors in <a href="/wiki/Branch_prediction" class="mw-redirect" title="Branch prediction">branch prediction</a> on modern <a href="/wiki/Central_processing_unit" title="Central processing unit">central processing units</a> (CPUs), and dramatically reduce performance. A notable example is highly optimized ray with axis aligned box intersection code in <a href="/wiki/Ray_tracing_(physics)" title="Ray tracing (physics)">ray tracing</a>.<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (November 2010)">clarification needed</span></a></i>]</sup> Some compilers can detect such cases and emit faster code, but programming language semantics may constrain such optimizations.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2016)">citation needed</span></a></i>]</sup> </p><p>An example of a compiler unable to optimize for such a case is <a href="/wiki/Java_(programming_language)" title="Java (programming language)">Java</a>'s <a href="/wiki/HotSpot_(virtual_machine)" title="HotSpot (virtual machine)">Hotspot virtual machine</a> (VM) as of 2012.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=11" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Don%27t-care_term" title="Don't-care term">Don't-care term</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Short-circuit_evaluation&action=edit&section=12" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><a href="/wiki/Edsger_W._Dijkstra" title="Edsger W. Dijkstra">Edsger W. Dijkstra</a> "On a somewhat disappointing correspondence", EWD1009-0, 25 May 1987 <a rel="nofollow" class="external text" href="http://www.cs.utexas.edu/users/EWD/ewd10xx/EWD1009.PDF">full text</a></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html">"Shell Command Language"</a>. <i>pubs.opengroup.org</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=pubs.opengroup.org&rft.atitle=Shell+Command+Language&rft_id=https%3A%2F%2Fpubs.opengroup.org%2Fonlinepubs%2F009695399%2Futilities%2Fxcu_chap02.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AShort-circuit+evaluation" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBergstraPonseStaudt2010" class="citation arxiv cs1">Bergstra, Jan A.; Ponse, A.; Staudt, D.J.C. (2010). "Short-circuit logic". <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1010.3674">1010.3674</a></span> [<a rel="nofollow" class="external text" href="https://arxiv.org/archive/cs.LO">cs.LO</a>].</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=preprint&rft.jtitle=arXiv&rft.atitle=Short-circuit+logic&rft.date=2010&rft_id=info%3Aarxiv%2F1010.3674&rft.aulast=Bergstra&rft.aufirst=Jan+A.&rft.au=Ponse%2C+A.&rft.au=Staudt%2C+D.J.C.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AShort-circuit+evaluation" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf">ISO/IEC 9899 standard, sections 6.2.5, 6.3.1.2, 6.5 and 7.16.</a></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf">ISO/IEC 9899 standard, section 6.5.13</a></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3092.pdf">ISO/IEC IS 14882 draft.</a></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://v2.ocaml.org/manual/expr.html#ss:expr-operators">"OCaml - the OCaml language"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=OCaml+-+the+OCaml+language&rft_id=https%3A%2F%2Fv2.ocaml.org%2Fmanual%2Fexpr.html%23ss%3Aexpr-operators&rfr_id=info%3Asid%2Fen.wikipedia.org%3AShort-circuit+evaluation" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://docs.ruby-lang.org/en/3.3/syntax/operators_rdoc.html#label-Logical+Operators">"operators - Documentation for Ruby 3.3"</a>. <i>docs.ruby-lang.org</i><span class="reference-accessdate">. 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Retrieved <span class="nowrap">2019-01-09</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=What+does+%7C%7C+mean+in+bash%3F&rft.pub=stackexchange.com&rft_id=https%3A%2F%2Funix.stackexchange.com%2Fquestions%2F190543%2Fwhat-does-mean-in-bash&rfr_id=info%3Asid%2Fen.wikipedia.org%3AShort-circuit+evaluation" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.itu.dk/people/sestoft/papers/SondergaardSestoft1990.pdf">"Referential Transparency, Definiteness and Unfoldability"</a> <span class="cs1-format">(PDF)</span>. Itu.dk<span class="reference-accessdate">. Retrieved <span class="nowrap">2013-08-24</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Referential+Transparency%2C+Definiteness+and+Unfoldability&rft.pub=Itu.dk&rft_id=http%3A%2F%2Fwww.itu.dk%2Fpeople%2Fsestoft%2Fpapers%2FSondergaardSestoft1990.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AShort-circuit+evaluation" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWasserman2012" class="citation web cs1">Wasserman, Louis (11 July 2012). <a rel="nofollow" class="external text" href="https://stackoverflow.com/a/11412121">"Java: What are the cases in which it is better to use unconditional AND (& instead of &&)"</a>. <i>Stack Overflow</i>.</cite><span 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