path: root/files/fr/référence_de_jsapi/index.html

---
title: Référence de JSAPI
slug: Référence_de_JSAPI
translation_of: Mozilla/Projects/SpiderMonkey/JSAPI_reference
---
<p><strong>JSAPI</strong> est l'implémentation en C du moteur JavaScript <a href="/en/SpiderMonkey" title="en/SpiderMonkey">SpiderMonkey</a>. Pour apprendre à utiliser JSAPI, lisez le <a href="/En/SpiderMonkey/JSAPI_User_Guide" title="en/JSAPI_User_Guide">Guide utilisateur JSAPI [en]</a> et le <a href="/En/SpiderMonkey/JSAPI_Cookbook" title="en/JSAPI_Cookbook">JSAPI Cookbook [en]</a>.</p>

<div class="note"><strong>Note :</strong> La page wiki consacrée à <a class="internal" href="/En/SpiderMonkey/FOSS" title="En/SpiderMonkey/FOSS">FOSS [en]</a> présente plusieurs liens vers différents outils et librarires pour faciliter l'utilisation quotidienne de SpiderMonkey et JSAPI.</div>

<div class="note"><strong>Note de traduction : </strong>l'essentiel des liens présentées ici ciblent des ressources en anglais. Le livre de référence de JSAPI étant en cours de traduction, les liens menant vers des ressources traduites en français seront suffixées du symbole [fr].</div>

<h3 id="Runtimes_and_contexts" name="Runtimes_and_contexts">Runtimes et contextes</h3>

<ul>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/JSRuntime" title="en/JSRuntime">JSRuntime</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewRuntime" title="en/JS_NewRuntime">JS_NewRuntime</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyRuntime" title="en/JS_DestroyRuntime">JS_DestroyRuntime</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ShutDown" title="en/JS_ShutDown">JS_ShutDown</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetRuntimePrivate" title="en/JS_GetRuntimePrivate">JS_GetRuntimePrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetRuntimePrivate" title="en/JS_GetRuntimePrivate">JS_SetRuntimePrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Init" title="en/JS_Init">JS_Init</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Finish" title="en/JS_Finish">JS_Finish</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ContextIterator" title="en/JS_ContextIterator">JS_ContextIterator</a></li>
</ul>

<ul>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/JSRuntime" title="en/JSRuntime">JSContext</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewContext" title="en/JS_NewContext">JS_NewContext</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyContext" title="en/JS_DestroyContext">JS_DestroyContext</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyContext" title="en/JS_DestroyContext">JS_DestroyContextMaybeGC</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyContext" title="en/JS_DestroyContext">JS_DestroyContextNoGC</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetRuntime" title="en/JS_GetRuntime">JS_GetRuntime</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetContextPrivate" title="en/JS_GetContextPrivate">JS_GetContextPrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetContextPrivate" title="en/JS_GetContextPrivate">JS_SetContextPrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetBranchCallback" title="en/JS_SetBranchCallback">JS_SetBranchCallback</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_SetOperationCallback</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_ClearOperationCallback</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_GetOperationCallback</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_GetOperationLimit</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_SetOperationLimit</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_MAX_OPERATION_LIMIT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOperationCallback" title="en/JS_SetOperationCallback">JS_OPERATION_WEIGHT_BASE</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetThreadStackLimit" title="en/JS_SetThreadStackLimit">JS_SetThreadStackLimit</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetScriptStackQuota" title="en/JS_SetScriptStackQuota">JS_SetScriptStackQuota</a></li>
</ul>

<ul>
 <li><em>Options: </em>JSOPTION_STRICT, JSOPTION_WERROR, JSOPTION_VAROBJFIX, JSOPTION_COMPILE_N_GO, JSOPTION_ATLINE, JSOPTION_XML, JSOPTION_RELIMIT, JSOPTION_NO_SCRIPT_RVAL, JSOPTION_UNROOTED_GLOBAL, JSOPTION_METHODJIT, JSOPTION_PROFILING, JSOPTION_METHODJIT_ALWAYS, JSOPTION_PCCOUNT, JSOPTION_TYPE_INFERENCE, JSOPTION_SOFTEN</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetOptions" title="en/JS_GetOptions">JS_GetOptions</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetOptions" title="en/JS_SetOptions">JS_SetOptions</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_ToggleOptions" title="en/JS_ToggleOptions">JS_ToggleOptions</a></li>
</ul>

<ul>
 <li>enum <a href="/En/SpiderMonkey/JSAPI_Reference/JSVersion" title="en/JSVersion">JSVersion</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JSVersion" title="en/JSVERSION_ECMA_3">JSVERSION_ECMA_3</a>, <a href="/en/JSVERSION_DEFAULT" title="en/JSVERSION_DEFAULT">JSVERSION_DEFAULT</a>, <a href="/en/JSVERSION_LATEST" title="en/JSVERSION_LATEST">JSVERSION_LATEST</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetImplementationVersion" title="en/JS_GetImplementationVersion">JS_GetImplementationVersion</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetVersion" title="en/JS_GetVersion">JS_GetVersion</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetVersion" title="en/JS_SetVersion">JS_SetVersion</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_StringToVersion" title="en/JS_StringToVersion">JS_StringToVersion</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_VersionToString" title="en/JS_VersionToString">JS_VersionToString</a></li>
</ul>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetGlobalForScopeChain" title="en/JS_GetGlobalForScopeChain">JS_GetGlobalForScopeChain</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetGlobalObject" title="en/JS_GetGlobalObject">JS_GetGlobalObject </a>{{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGlobalObject" title="en/JS_SetGlobalObject">JS_SetGlobalObject</a> {{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InitClass" title="en/JS_InitClass">JS_InitClass</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InitStandardClasses" title="en/JS_InitStandardClasses">JS_InitStandardClasses</a></li>
 <li><a href="/en/JS_ResolveStandardClass" title="en/JS_ResolveStandardClass">JS_ResolveStandardClass</a></li>
 <li><a href="/en/JS_EnumerateStandardClasses" title="en/JS_EnumerateStandardClasses">JS_EnumerateStandardClasses</a></li>
 <li><a href="/en/JS_EnumerateResolvedStandardClasses" title="en/JS_EnumerateResolvedStandardClasses">JS_EnumerateResolvedStandardClasses</a></li>
</ul>

<ul>
 <li><a href="/en/JS_IsAssigning" title="en/JS_IsAssigning">JS_IsAssigning</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IsConstructing" title="en/JS_IsConstructing">JS_IsConstructing</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IsRunning" title="en/JS_IsRunning">JS_IsRunning</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetScopeChain" title="en/JS_GetScopeChain">JS_GetScopeChain</a>{{ obsolete_inline() }}</li>
 <li><a href="/en/JS_SaveFrameChain" title="en/JS_SaveFrameChain">JS_SaveFrameChain</a>, <a href="/en/JS_RestoreFrameChain" title="en/JS_RestoreFrameChain">JS_RestoreFrameChain</a></li>
</ul>

<p>Compartiments :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewCompartmentAndGlobalObject" title="en/SpiderMonkey/JSAPI Reference/JS NewCompartmentAndGlobalObject">JS_NewCompartmentAndGlobalObject</a> {{ Jsapi_minversion_inline("1.8.1") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EnterCrossCompartmentCall" title="en/SpiderMonkey/JSAPI Reference/JS EnterCrossCompartmentCall">JS_EnterCrossCompartmentCall</a> {{ Jsapi_minversion_inline("1.8.1") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LeaveCrossCompartmentCall" title="en/SpiderMonkey/JSAPI Reference/JS LeaveCrossCompartmentCall">JS_LeaveCrossCompartmentCall</a> {{ Jsapi_minversion_inline("1.8.1") }}</li>
</ul>

<p>Méthodes de locales :</p>

<ul>
 <li>struct <a href="/en/JSLocaleCallbacks" title="en/JSLocaleCallbacks">JSLocaleCallbacks</a></li>
 <li><a href="/en/JS_GetLocaleCallbacks" title="en/JS_GetLocaleCallbacks">JS_GetLocaleCallbacks</a></li>
 <li><a href="/en/JS_SetLocaleCallbacks" title="en/JS_SetLocaleCallbacks">JS_SetLocaleCallbacks</a></li>
</ul>

<p>Types de méthodes de locales :</p>

<ul>
 <li><a href="/en/JSLocaleToUpperCase" title="en/JSLocaleToUpperCase">JSLocaleToUpperCase</a></li>
 <li><a href="/en/JSLocaleToLowerCase" title="en/JSLocaleToLowerCase">JSLocaleToLowerCase</a></li>
 <li><a href="/en/JSLocaleCompare" title="en/JSLocaleCompare">JSLocaleCompare</a></li>
 <li><a href="/en/JSLocaleToUnicode" title="en/JSLocaleToUnicode">JSLocaleToUnicode</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JSErrorCallback</a></li>
</ul>

<h3 id="Scripts" name="Scripts">Scripts</h3>

<p>Exécution simple de code JavaScript :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EvaluateScript" title="en/JS_EvaluateScript">JS_EvaluateScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EvaluateScript" title="en/JS_EvaluateScript">JS_EvaluateUCScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EvaluateScriptForPrincipals" title="en/JS_EvaluateScriptForPrincipals">JS_EvaluateScriptForPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EvaluateScriptForPrincipals" title="en/JS_EvaluateScriptForPrincipals">JS_EvaluateUCScriptForPrincipals</a></li>
</ul>

<p>Exécution compilée de code JavaScript dans un objet <code>JSScript</code> exécutable à la volée :</p>

<ul>
 <li>typedef <a href="/en/JSScript" title="en/JSScript">JSScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFile" title="en/JS_CompileFile">JS_CompileFile</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFileHandle" title="en/JS_CompileFileHandle">JS_CompileFileHandle</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFileHandle" title="en/JS_CompileFileHandle">JS_CompileFileHandleForPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileScript" title="en/JS_CompileScript">JS_CompileScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileScript" title="en/JS_CompileScript">JS_CompileUCScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileScriptForPrincipals" title="en/JS_CompileScriptForPrincipals">JS_CompileScriptForPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileScriptForPrincipals" title="en/JS_CompileScriptForPrincipals">JS_CompileUCScriptForPrincipals</a></li>
 <li><a href="/en/JS_BufferIsCompilableUnit" title="en/JS_BufferIsCompilableUnit">JS_BufferIsCompilableUnit</a></li>
 <li><a href="/en/JS_GetScriptObject" title="en/JS_GetScriptObject">JS_GetScriptObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewScriptObject" title="en/JS_NewScriptObject">JS_NewScriptObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ExecuteScript" title="en/JS_ExecuteScript">JS_ExecuteScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ExecuteScriptPart" title="en/JS_ExecuteScriptPart">JS_ExecuteScriptPart</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DecompileScript" title="en/JS_DecompileScript">JS_DecompileScript</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyScript" title="en/JS_DestroyScript">JS_DestroyScript</a></li>
</ul>

<p>Compilation de code JavaScript dans une fonction :</p>

<ul>
 <li>typedef <a href="/En/SpiderMonkey/JSAPI_Reference/JSFunction" title="en/JSFunction">JSFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFunction" title="en/JS_CompileFunction">JS_CompileFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFunctionForPrincipals" title="en/JS_CompileFunctionForPrincipals">JS_CompileFunctionForPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFunction" title="en/JS_CompileFunction">JS_CompileUCFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompileFunctionForPrincipals" title="en/JS_CompileFunctionForPrincipals">JS_CompileUCFunctionForPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DecompileFunction" title="en/JS_DecompileFunction">JS_DecompileFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DecompileFunctionBody" title="en/JS_DecompileFunctionBody">JS_DecompileFunctionBody</a></li>
</ul>

<h3 id="Error_handling" name="Error_handling">Gestion des erreurs</h3>

<ul>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSErrorReport" title="en/JSErrorReport">JSErrorReport</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportError" title="en/JS_ReportError">JS_ReportError</a></li>
 <li><a href="/en/JS_ReportWarning" title="en/JS_ReportWarning">JS_ReportWarning</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JS_ReportErrorNumber</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JS_ReportErrorNumberUC</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JS_ReportErrorFlagsAndNumber</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JS_ReportErrorFlagsAndNumberUC</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportOutOfMemory" title="en/JS_ReportOutOfMemory">JS_ReportOutOfMemory</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetErrorReporter" title="en/JS_SetErrorReporter">JS_SetErrorReporter</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSREPORT_IS_EXCEPTION" title="en/JSREPORT_IS_EXCEPTION">JSREPORT_IS_EXCEPTION</a></li>
 <li><a href="/en/JSREPORT_IS_STRICT" title="en/JSREPORT_IS_STRICT">JSREPORT_IS_STRICT</a></li>
 <li><a href="/en/JSREPORT_IS_WARNING" title="en/JSREPORT_IS_WARNING">JSREPORT_IS_WARNING</a></li>
</ul>

<p>Méthodes C/C++ de levée et de capture d'exceptions JavaScript :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IsExceptionPending" title="en/JS_IsExceptionPending">JS_IsExceptionPending</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPendingException" title="en/JS_GetPendingException">JS_GetPendingException</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPendingException" title="en/JS_SetPendingException">JS_SetPendingException</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearPendingException" title="en/JS_ClearPendingException">JS_ClearPendingException</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_ThrowStopIteration" title="en/JS_ThrowStopIteration">JS_ThrowStopIteration</a> {{ jsapi_minversion_inline("1.8") }}</li>
</ul>

<ul>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/JSExceptionState" title="en/JSExceptionState">JSExceptionState</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SaveExceptionState" title="en/JS_SaveExceptionState">JS_SaveExceptionState</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_RestoreExceptionState" title="en/JS_RestoreExceptionState">JS_RestoreExceptionState</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DropExceptionState" title="en/JS_DropExceptionState">JS_DropExceptionState</a></li>
</ul>

<p>Fonctions de conversion d'erreur JavaScript en exceptions (et inversement) :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportPendingException" title="en/JS_ReportPendingException">JS_ReportPendingException</a></li>
 <li><a href="/en/JS_ErrorFromException" title="en/JS_ErrorFromException">JS_ErrorFromException</a></li>
 <li><a href="/en/JS_ThrowReportedError" title="en/JS_ThrowReportedError">JS_ThrowReportedError</a></li>
</ul>

<h3 id="Values_and_types" name="Values_and_types">Types et valeurs</h3>

<ul>
 <li>typedef <a href="/En/SpiderMonkey/JSAPI_Reference/Jsval" title="en/jsval">jsval</a></li>
</ul>

<p>Constantes <code>jsval</code> :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_NULL" title="en/JSVAL_NULL">JSVAL_NULL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_VOID" title="en/JSVAL_VOID">JSVAL_VOID</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TRUE" title="en/JSVAL_TRUE">JSVAL_TRUE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TRUE" title="en/JSVAL_TRUE">JSVAL_FALSE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_ZERO" title="en/JSVAL_ZERO">JSVAL_ZERO</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_ONE" title="en/JSVAL_ONE">JSVAL_ONE</a></li>
</ul>

<p>Fonctions et macros de détermination de types <code>jsval</code>:</p>

<ul>
 <li>enum <a href="/en/SpiderMonkey/JSAPI_Reference/JSType" title="en/JSType">JSType</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_TypeOfValue" title="en/JS_TypeOfValue">JS_TypeOfValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_NULL" title="en/JSVAL_IS_NULL">JSVAL_IS_NULL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_VOID" title="en/JSVAL_IS_VOID">JSVAL_IS_VOID</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_BOOLEAN" title="en/JSVAL_IS_BOOLEAN">JSVAL_IS_BOOLEAN</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_NUMBER" title="en/JSVAL_IS_NUMBER">JSVAL_IS_NUMBER</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_INT" title="en/JSVAL_IS_INT">JSVAL_IS_INT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_DOUBLE" title="en/JSVAL_IS_DOUBLE">JSVAL_IS_DOUBLE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_STRING" title="en/JSVAL_IS_STRING">JSVAL_IS_STRING</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_OBJECT" title="en/JSVAL_IS_OBJECT">JSVAL_IS_OBJECT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_PRIMITIVE" title="en/JSVAL_IS_PRIMITIVE">JSVAL_IS_PRIMITIVE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_IS_GCTHING" title="en/JSVAL_IS_GCTHING">JSVAL_IS_GCTHING</a></li>
</ul>

<p>Méthodes haut-niveau de conversion de types pour l'encapsulation/désencapsulation d'arguments de fonctions.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PushArguments" title="en/JS_PushArguments">JS_PushArguments</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PushArguments" title="en/JS_PushArguments">JS_PushArgumentsVA</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PopArguments" title="en/JS_PopArguments">JS_PopArguments</a></li>
</ul>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConvertArguments" title="en/JS_ConvertArguments">JS_ConvertArguments</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConvertArgumentsVA" title="en/JS_ConvertArgumentsVA">JS_ConvertArgumentsVA</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddArgumentFormatter" title="en/JS_AddArgumentFormatter">JS_AddArgumentFormatter</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddArgumentFormatter" title="en/JS_AddArgumentFormatter">JS_RemoveArgumentFormatter</a></li>
</ul>

<p>Conversions de types JavaScript. Ces méthodes peuvent être appliquées à n'importe-quel type de variable <code>jsval</code>s. Elles peuvent potentiellement retourner des objets. Par exemple, <code>JS_ValueToObject(cx, s)</code> où <code>s</code> est une chaîne de caractères renvoie un nouvel objet de type <code>String</code>. Ces fonctions peuvent appeler des méthodes JavaScript. Par exemple, <code>JS_ValueToString(cx, obj)</code> peut appeler <code>obj.toString()</code>.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToBoolean" title="en/JS_ValueToBoolean">JS_ValueToBoolean</a></li>
 <li><a href="/en/JS_ValueToConstructor" title="en/JS_ValueToConstructor">JS_ValueToConstructor</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToECMAInt32" title="en/JS_ValueToECMAInt32">JS_ValueToECMAInt32</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToECMAInt32" title="en/JS_ValueToECMAInt32">JS_ValueToECMAUint32</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToFunction" title="en/JS_ValueToFunction">JS_ValueToFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToInt32" title="en/JS_ValueToInt32">JS_ValueToInt32</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToNumber" title="en/JS_ValueToNumber">JS_ValueToNumber</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToObject" title="en/JS_ValueToObject">JS_ValueToObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToString" title="en/JS_ValueToString">JS_ValueToString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToECMAInt32" title="en/JS_ValueToECMAInt32">JS_ValueToUint16</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConvertValue" title="en/JS_ConvertValue">JS_ConvertValue</a></li>
</ul>

<p>Macros à éxecution rapide sans contrôle de type. Ces macros ne doivent pas être appliquées à des valeurs dont le type n'est pas précisément connu au départ. Comme les 'casts' C, elles peuvent planter l'éxecution si elles sont appliquées à des types/valeurs incorrectes. Elles ne renvoient jamais d'objet et n'appellent jamais de code JavaScript directement.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_BOOLEAN" title="en/JSVAL_TO_BOOLEAN">JSVAL_TO_BOOLEAN</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/BOOLEAN_TO_JSVAL" title="en/BOOLEAN_TO_JSVAL">BOOLEAN_TO_JSVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_INT" title="en/JSVAL_TO_INT">JSVAL_TO_INT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/INT_TO_JSVAL" title="en/INT_TO_JSVAL">INT_TO_JSVAL</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/INT_FITS_IN_JSVAL" title="en/INT_FITS_IN_JSVAL">INT_FITS_IN_JSVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_DOUBLE" title="en/JSVAL_TO_DOUBLE">JSVAL_TO_DOUBLE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/DOUBLE_TO_JSVAL" title="en/DOUBLE_TO_JSVAL">DOUBLE_TO_JSVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_OBJECT" title="en/JSVAL_TO_OBJECT">JSVAL_TO_OBJECT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/OBJECT_TO_JSVAL" title="en/OBJECT_TO_JSVAL">OBJECT_TO_JSVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_STRING" title="en/JSVAL_TO_STRING">JSVAL_TO_STRING</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/STRING_TO_JSVAL" title="en/STRING_TO_JSVAL">STRING_TO_JSVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_TO_GCTHING" title="en/JSVAL_TO_GCTHING">JSVAL_TO_GCTHING</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/PRIVATE_TO_JSVAL" title="en/PRIVATE_TO_JSVAL">JSVAL_TO_PRIVATE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/PRIVATE_TO_JSVAL" title="en/PRIVATE_TO_JSVAL">PRIVATE_TO_JSVAL</a></li>
</ul>

<p>Function de retour de type (équivalent à <code>typeof</code>) :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetTypeName" title="en/JS_GetTypeName">JS_GetTypeName</a></li>
</ul>

<p>Functions de comparaison :</p>

<ul>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_StrictlyEqual" title="En/SpiderMonkey/JSAPI_Reference/JS_StrictlyEqual">JS_StrictlyEqual</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LooselyEqual" title="En/SpiderMonkey/JSAPI Reference/JS LooselyEqual">JS_LooselyEqual</a></li>
</ul>

<h3 id="Memory_management" name="Memory_management">Gestion de la mémoire</h3>

<p>Ces fonctions se comportent comme les méthodes C Standard de type <code>malloc</code>, à l'exception des erreurs qui sont rapportées via les APIs de gestion d'erreur de SPiderMonkey plutôt que via <code>errno</code>. Ces fonctions autorisent également SpiderMonkey à contrôler la quantité de bits alloués en mémoire :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_malloc" title="en/JS_malloc">JS_malloc</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_malloc" title="en/JS_free">JS_free</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_malloc" title="en/JS_realloc">JS_realloc</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_malloc" title="en/JS_strdup">JS_strdup</a></li>
</ul>

<p>Objets JavaScripts, chaînes de caractères, et nombres à virgule flottante sont gérés par le ramasse-miette. Ces fonctions permettent d'accéder à la gestion du ramasse-miette :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GC" title="en/JS_GC">JS_GC</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_MaybeGC" title="en/JS_MaybeGC">JS_MaybeGC</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JS_GetGCParameter</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JS_SetGCParameter</a>, enum <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JSGCParamKey</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JSGC_MAX_BYTES</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JSGC_MAX_MALLOC_BYTES</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/JS_SetGCParameter">JSGC_STACKPOOL_LIFESPAN</a>, <a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/SpiderMonkey/JSAPI Reference/JSGC TRIGGER FACTOR">JSGC_TRIGGER_FACTOR</a>, <a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/SpiderMonkey/JSAPI Reference/JSGC BYTES">JSGC_BYTES</a>, <a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetGCParameter" title="en/SpiderMonkey/JSAPI Reference/JSGC NUMBER">JSGC_NUMBER</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JS_SetGCCallback</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JS_SetGCCallbackRT</a>, enum <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGCStatus</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGC_BEGIN</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGC_MARK_END</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGC_FINALIZE_END</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGC_END</a></li>
 <li><a href="/En/JS_MarkGCThing" title="en/JS_MarkGCThing">JS_MarkGCThing</a></li>
 <li><a href="/En/JS_IsAboutToBeFinalized" title="en/JS_IsAboutToBeFinalized">JS_IsAboutToBeFinalized</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearNewbornRoots" title="en/JS_ClearNewbornRoots">JS_ClearNewbornRoots</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCZeal" title="en/JS_SetGCZeal">JS_SetGCZeal</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DumpHeap" title="en/JS_DumpHeap">JS_DumpHeap</a> {{ Jsapi_minversion_inline("1.8") }}</li>
</ul>

<p>Le reste de ces APIs permet de protéger les objets en mémoire de leur destruction par le ramasse-miette avant que l'application n'ai cessé de les utiliser.</p>

<p>Si une variable est racine (<em>root</em>), tout élément pointé en référence par cette variable ne sera pas collectée par le ramasse-miette. Des erreurs dans la gestion des variables racines sont une cause fréquente de plantages inexpliqués difficiles à détecter.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddRoot" title="en/JS_AddRoot">JS_AddRoot</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddRoot" title="en/JS_AddRoot">JS_AddNamedRoot</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddRoot" title="en/JS_AddRoot">JS_AddNamedRootRT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_RemoveRoot" title="en/JS_RemoveRoot">JS_RemoveRoot</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_RemoveRootRT" title="en/JS_RemoveRootRT">JS_RemoveRootRT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MapGCRoots">JS_MapGCRoots</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JSGCMapRootFun">JSGCMapRootFun</a> – <a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MAP_GCROOT_NEXT">JS_MAP_GCROOT_NEXT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MAP_GCROOT_REMOVE">JS_MAP_GCROOT_REMOVE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MAP_GCROOT_STOP">JS_MAP_GCROOT_STOP</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DumpNamedRoots" title="en/JS_DumpNamedRoots">JS_DumpNamedRoots</a></li>
</ul>

<p>L'utilisation de portées locales des variables racines sont une autre méthode de prévenir les objets du passage du ramasse-miette.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EnterLocalRootScope" title="en/JS_EnterLocalRootScope">JS_EnterLocalRootScope</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LeaveLocalRootScope" title="en/JS_LeaveLocalRootScope">JS_LeaveLocalRootScope</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LeaveLocalRootScopeWithResult" title="en/JS_LeaveLocalRootScopeWithResult">JS_LeaveLocalRootScopeWithResult</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ForgetLocalRoot" title="en/JS_ForgetLocalRoot">JS_ForgetLocalRoot</a></li>
</ul>

<p>{{ Jsapi_minversion_inline("1.8") }} Si un objet contient des références vers d'autres éléments dans le ramasse-miette qui ne sont pas stockés bia le moteur de structure de données (<em>slots</em>) de SpiderMonkey, il doit implémenter la méthode <code><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.mark" title="en/JSClass.mark">JSTraceOp</a></code> pour permettre au ramasse-miette de traverser ses objets référencés. Autrement, le ramasse-miette ne pourra pas détecter et collecter les objets potentiellement éligibles, provoquant un plantage. (Dans SpiderMonkey 1.7 et antérieur, la méthode <code>JSMarkOp</code> est utilisée. Cette méthode est notée <em>deprecated</em> dans la version 1.8 de SpiderMonkey à venir.)</p>

<p>Les APIs de traçage sont utilisées par le ramasse-miette et la méthode <code>JSMarkOp</code>. Les applications JSAPI peuvent également les utiliser pour examiner le contenu des objets. (Par exemple, ces APIs procurent une interaction fine entre le ramasse-miette JavaScript et les autres types de ramasse-miette.)</p>

<ul>
 <li><a href="/en/JSVAL_IS_TRACEABLE" title="en/JSVAL_IS_TRACEABLE">JSVAL_IS_TRACEABLE</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JSVAL_TO_TRACEABLE" title="en/JSVAL_TO_TRACEABLE">JSVAL_TO_TRACEABLE</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JSVAL_TRACE_KIND" title="en/JSVAL_TRACE_KIND">JSVAL_TRACE_KIND</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li>struct <a href="/en/JSTracer" title="en/JSTracer">JSTracer</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_TRACER_INIT" title="en/JS_TRACER_INIT">JS_TRACER_INIT</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CallTracer" title="en/JS_CallTracer">JS_CallTracer</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SET_TRACING_DETAILS" title="en/JS_SET_TRACING_DETAILS">JS_SET_TRACING_DETAILS</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_SET_TRACING_INDEX" title="en/JS_SET_TRACING_INDEX">JS_SET_TRACING_INDEX</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_SET_TRACING_NAME" title="en/JS_SET_TRACING_NAME">JS_SET_TRACING_NAME</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CALL_TRACER" title="en/JS_CALL_TRACER">JS_CALL_TRACER</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CALL_VALUE_TRACER" title="en/JS_CALL_VALUE_TRACER">JS_CALL_VALUE_TRACER</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CALL_OBJECT_TRACER" title="en/JS_CALL_OBJECT_TRACER">JS_CALL_OBJECT_TRACER</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CALL_STRING_TRACER" title="en/JS_CALL_STRING_TRACER">JS_CALL_STRING_TRACER</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_CALL_DOUBLE_TRACER" title="en/JS_CALL_DOUBLE_TRACER">JS_CALL_DOUBLE_TRACER</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_TraceChildren" title="en/JS_TraceChildren">JS_TraceChildren</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_TraceRuntime" title="en/JS_TraceRuntime">JS_TraceRuntime</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/JS_PrintTraceThingInfo" title="en/JS_PrintTraceThingInfo">JS_PrintTraceThingInfo</a> (DEBUG-only) {{ Jsapi_minversion_inline("1.8") }}</li>
</ul>

<p>APIs du ramasse-miette diverses :</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_LOCK" title="en/JSVAL_LOCK">JSVAL_LOCK</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSVAL_UNLOCK" title="en/JSVAL_UNLOCK">JSVAL_UNLOCK</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LockGCThing" title="en/JS_LockGCThing">JS_LockGCThing</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/JS_LockGCThingRT" title="en/JS_LockGCThingRT">JS_LockGCThingRT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LockGCThing" title="en/JS_LockGCThing">JS_UnlockGCThing</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/JS_UnlockGCThingRT" title="en/JS_UnlockGCThingRT">JS_UnlockGCThingRT</a></li>
</ul>

<h3 id="Numbers" name="Numbers">Numbers</h3>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewNumberValue" title="en/JS_NewNumberValue">JS_NewNumberValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewDoubleValue" title="en/JS_NewDoubleValue">JS_NewDoubleValue</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewDouble" title="en/JS_NewDouble">JS_NewDouble</a>{{ obsolete_inline() }}</li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSConstDoubleSpec" title="en/JSConstDoubleSpec">JSConstDoubleSpec</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineConstDoubles" title="en/JS_DefineConstDoubles">JS_DefineConstDoubles</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetNaNValue" title="en/JS_GetNaNValue">JS_GetNaNValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPositiveInfinityValue" title="en/JS_GetPositiveInfinityValue">JS_GetNegativeInfinityValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPositiveInfinityValue" title="en/JS_GetPositiveInfinityValue">JS_GetPositiveInfinityValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DoubleToInt32" title="en/SpiderMonkey/JSAPI Reference/JS DoubleToInt32">JS_DoubleToInt32</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DoubleToInt32" title="en/SpiderMonkey/JSAPI Reference/JS DoubleToInt32">JS_DoubleToUint32</a> {{ Jsapi_minversion_inline("1.8.6") }}</li>
</ul>

<h3 id="Strings" name="Strings">Strings</h3>

<ul>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/JSString" title="en/JSString">JSString</a></li>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/jschar" title="en/jschar">jschar</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewString" title="en/JS_NewString">JS_NewString</a> {{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyN" title="en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyN">JS_NewStringCopyN</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyZ" title="en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyZ">JS_NewStringCopyZ</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewString" title="en/JS_NewString">JS_NewUCString</a> {{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyN" title="en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyN">JS_NewUCStringCopyN</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyZ" title="en/SpiderMonkey/JSAPI_Reference/JS_NewStringCopyZ">JS_NewUCStringCopyZ</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewGrowableString" title="en/JS_NewGrowableString">JS_NewGrowableString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewDependentString" title="en/SpiderMonkey/JSAPI_Reference/JS_NewDependentString">JS_NewDependentString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetEmptyStringValue" title="en/SpiderMonkey/JSAPI_Reference/JS_GetEmptyStringValue">JS_GetEmptyStringValue</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetEmptyString" title="JS_GetEmptyString"><code>JS_GetEmptyString()</code></a> {{ jsapi_minversion_inline("1.8.5") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CompareStrings" title="en/SpiderMonkey/JSAPI_Reference/JS_CompareStrings">JS_CompareStrings</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConcatStrings" title="en/JS_ConcatStrings">JS_ConcatStrings</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes" title="en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes">JS_GetStringBytes</a> {{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes" title="en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes">JS_GetStringBytesZ</a> {{ obsolete_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringChars" title="en/SpiderMonkey/JSAPI_Reference/JS_GetStringChars">JS_GetStringChars</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringCharsAndLength" title="JS_GetStringCharsAndLength">JS_GetStringCharsAndLength</a></li>
 <li>JS_GetStringCharsZ</li>
 <li>JS_GetStringCharsZAndLength</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringLength" title="en/SpiderMonkey/JSAPI_Reference/JS_GetStringLength">JS_GetStringLength</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_MakeStringImmutable" title="en/SpiderMonkey/JSAPI_Reference/JS_MakeStringImmutable">JS_MakeStringImmutable</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_UndependString" title="en/SpiderMonkey/JSAPI_Reference/JS_UndependString">JS_UndependString</a></li>
</ul>

<ul>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_CStringsAreUTF8" title="en/JS_CStringsAreUTF8">JS_CStringsAreUTF8</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_CStringsAreUTF8" title="en/JS_SetCStringsAreUTF8">JS_SetCStringsAreUTF8</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DecodeBytes" title="en/JS_DecodeBytes">JS_DecodeBytes</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_EncodeCharacters" title="en/JS_EncodeCharacters">JS_EncodeCharacters</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes" title="en/SpiderMonkey/JSAPI Reference/JS GetStringBytes">JS_EncodeString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes" title="en/SpiderMonkey/JSAPI Reference/JS GetStringBytes">JS_EncodeStringToBuffer</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetStringBytes" title="en/SpiderMonkey/JSAPI Reference/JS GetStringBytes">JS_GetStringEncodingLength</a></li>
</ul>

<p><em>Interning</em> strings tells the SpiderMonkey engine to reuse existing string objects when possible.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InternString" title="en/SpiderMonkey/JSAPI_Reference/JS_InternString">JS_InternString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InternString" title="en/SpiderMonkey/JSAPI_Reference/JS_InternString">JS_InternUCString</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InternString" title="en/SpiderMonkey/JSAPI_Reference/JS_InternString">JS_InternUCStringN</a></li>
</ul>

<p>The character data for <em>external strings</em> is stored in memory provided by the application. Applications can use this to avoid copying data back and forth between SpiderMonkey's heap and application memory.</p>

<ul>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddExternalStringFinalizer" title="en/JS_AddExternalStringFinalizer">JS_AddExternalStringFinalizer()</a></code></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_RemoveExternalStringFinalizer" title="en/JS_RemoveExternalStringFinalizer">JS_RemoveExternalStringFinalizer()</a></code></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetExternalStringGCType" title="en/JS_GetExternalStringGCType">JS_GetExternalStringGCType()</a></code></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewExternalString" title="en/JS_NewExternalString">JS_NewExternalString()</a></code></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewExternalString" title="en/SpiderMonkey/JSAPI Reference/JS NewExternalString">JS_NewExternalStringWithClosure()</a></code></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetExternalStringClosure" title="en/SpiderMonkey/JSAPI Reference/JS GetExternalStringClosure">JS_GetExternalStringClosure()</a></code></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IsExternalString" title="en/SpiderMonkey/JSAPI Reference/JS IsExternalString"><code>JS_IsExternalString()</code></a></li>
</ul>

<h3 id="Objects" name="Objects">Objects</h3>

<ul>
 <li>typedef <a href="/en/SpiderMonkey/JSAPI_Reference/JSObject" title="en/JSObject">JSObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConstructObject" title="en/JS_ConstructObject">JS_ConstructObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ConstructObject" title="en/JS_ConstructObjectWithArguments">JS_ConstructObjectWithArguments</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineObject" title="en/JS_DefineObject">JS_DefineObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewObject" title="en/JS_NewObject">JS_NewObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewObjectForConstructor" title="en/SpiderMonkey/JSAPI_Reference/JS_NewObjectForConstructor">JS_NewObjectForConstructor</a> {{ Jsapi_minversion_inline("1.9") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewGlobalObject" title="en/SpiderMonkey/JSAPI Reference/JS NewGlobalObject">JS_NewGlobalObject</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewObject" title="en/JS_NewObject">JS_NewObjectWithGivenProto</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_New" title="en/SpiderMonkey/JSAPI Reference/JS New">JS_New</a></li>
</ul>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GET_CLASS" title="en/JS_GET_CLASS">JS_GET_CLASS </a><span>{{ obsolete_inline("js1.8.8") }}</span></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetClass" title="en/SpiderMonkey/JSAPI_Reference/JS_GetClass">JS_GetClass</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetObjectPrototype" title="en/JS_GetObjectPrototype">JS_GetObjectPrototype</a> {{ Jsapi_minversion_inline("1.9") }}</li>
 <li><a href="/en/JS_GetClassObject" title="en/JS_GetClassObject">JS_GetClassObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetConstructor" title="en/JS_GetConstructor">JS_GetConstructor</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetGlobalForObject" title="en/JS_GetGlobalForObject">JS_GetGlobalForObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetInstancePrivate" title="en/JS_GetInstancePrivate">JS_GetInstancePrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetParent" title="en/JS_GetParent">JS_GetParent</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetParent" title="en/JS_SetParent">JS_SetParent</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPrivate" title="en/JS_GetPrivate">JS_GetPrivate</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPrivate" title="en/JS_SetPrivate">JS_SetPrivate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPrototype" title="en/JS_GetPrototype">JS_GetPrototype</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPrototype" title="en/JS_SetPrototype">JS_SetPrototype</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetReservedSlot" title="en/JS_GetReservedSlot">JS_GetReservedSlot</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetReservedSlot" title="en/JS_GetReservedSlot">JS_SetReservedSlot</a></li>
 <li><a href="/en/JS_HasInstance" title="en/JS_HasInstance">JS_HasInstance</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InstanceOf" title="en/JS_InstanceOf">JS_InstanceOf</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SealObject" title="en/JS_SealObject">JS_SealObject</a> <span>{{ obsolete_inline("js1.8.5") }}</span></li>
</ul>

<h3 id="Date">Date</h3>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewDateObject" title="JS NewDateObject"><code>JS_NewDateObject()</code></a> {{ jsapi_minversion_inline("1.8.5") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewDateObjectMsec" title="JS_NewDateObjectMsec"><code>JS_NewDateObjectMsec()</code></a> {{ jsapi_minversion_inline("1.8.5") }}</li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ObjectIsDate" title="JS ObjectIsDate">JS_ObjectIsDate()</a></code></li>
</ul>

<h3 id="Properties" name="Properties">Properties</h3>

<p>These functions correspond directly to the ways scripts access object properties:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetProperty" title="en/JS_GetProperty">JS_GetProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetProperty" title="en/JS_GetProperty">JS_GetUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetProperty" title="en/JS_GetProperty">JS_GetPropertyById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetProperty" title="en/JS_SetProperty">JS_SetProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetProperty" title="en/JS_SetProperty">JS_SetUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetProperty" title="en/JS_SetProperty">JS_SetPropertyById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_HasProperty" title="en/JS_HasProperty">JS_HasProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_HasProperty" title="en/JS_HasProperty">JS_HasUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_HasProperty" title="en/JS_HasProperty">JS_HasPropertyById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteProperty" title="en/JS_DeleteProperty">JS_DeleteProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteProperty" title="en/JS_DeleteProperty">JS_DeletePropertyById</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteProperty2" title="en/JS_DeleteProperty2">JS_DeleteProperty2</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteProperty2" title="en/JS_DeleteProperty2">JS_DeleteUCProperty2</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteProperty2" title="en/JS_DeleteProperty2">JS_DeletePropertyById2</a></li>
</ul>

<p>The following functions are lower-level, allowing the JSAPI application more access to details of how properties are implemented. "Define" is a lower-level version of "set" that provides access to extra settings and does not call setters. Similarly, "lookup" is a lower-level version of "get" that offers extra options and does not call getters.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AlreadyHasOwnProperty" title="en/JS_AlreadyHasOwnElement">JS_AlreadyHasOwnElement</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AlreadyHasOwnProperty" title="en/JS_AlreadyHasOwnProperty">JS_AlreadyHasOwnProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AlreadyHasOwnProperty" title="en/JS_AlreadyHasOwnProperty">JS_AlreadyHasOwnUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AlreadyHasOwnProperty" title="en/JS_AlreadyHasOwnProperty">JS_AlreadyHasOwnPropertyById</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearScope" title="en/JS_ClearScope">JS_ClearScope</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineProperties" title="en/JS_DefineProperties">JS_DefineProperties</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineProperty" title="en/JS_DefineProperty">JS_DefineProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineProperty" title="en/JS_DefineProperty">JS_DefineUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineProperty" title="en/JS_DefineProperty">JS_DefinePropertyById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefinePropertyWithTinyId" title="en/JS_DefinePropertyWithTinyId">JS_DefinePropertyWithTinyId</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefinePropertyWithTinyId" title="en/JS_DefinePropertyWithTinyId">JS_DefineUCPropertyWithTinyId</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Enumerate" title="en/JS_Enumerate">JS_Enumerate</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JS_GetPropertyAttributes</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JS_GetUCPropertyAttributes</a> – <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_ENUMERATE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_EXPORTED</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_GETTER</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_INDEX</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_PERMANENT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_READONLY</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_SETTER</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttributes" title="en/JS_GetPropertyAttributes">JSPROP_SHARED</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttrsGetterAndSetter" title="en/JS_GetPropertyAttrsGetterAndSetter">JS_GetPropertyAttrsGetterAndSetter</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttrsGetterAndSetter" title="en/JS_GetPropertyAttrsGetterAndSetter">JS_GetUCPropertyAttrsGetterAndSetter</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyAttrsGetterAndSetter" title="en/JS_GetPropertyAttrsGetterAndSetter">JS_GetPropertyAttrsGetterAndSetterById</a></li>
 <li><a class="internal" href="/en/SpiderMonkey/JSAPI_Reference/JS_GetPropertyDescriptorById" title="en/SpiderMonkey/JSAPI Reference/JS GetPropertyDescriptorById">JS_GetPropertyDescriptorById</a> {{ Jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupProperty" title="en/JS_LookupProperty">JS_LookupProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupProperty" title="en/JS_LookupProperty">JS_LookupUCProperty</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupProperty" title="en/JS_LookupProperty">JS_LookupPropertyById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupProperty" title="en/JS_LookupProperty">JS_LookupPropertyWithFlags</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupProperty" title="en/JS_LookupProperty">JS_LookupPropertyWithFlagsById</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewPropertyIterator" title="en/JS_NewPropertyIterator">JS_NewPropertyIterator</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NextProperty" title="en/JS_NextProperty">JS_NextProperty</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPropertyAttributes" title="en/JS_SetPropertyAttributes">JS_SetPropertyAttributes</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPropertyAttributes" title="en/JS_SetPropertyAttributes">JS_SetUCPropertyAttributes</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AliasProperty" title="en/JS_AliasProperty">JS_AliasProperty</a> {{ obsolete_inline() }}</li>
</ul>

<p>The following functions behave like <code>JS_GetProperty</code> and <code>JS_GetPropertyById</code> except when operating on E4X XML objects.</p>

<ul>
 <li><a href="/en/JS_GetMethod" title="en/JS_GetMethod">JS_GetMethod</a>, <a href="/En/JS_GetMethodById" title="en/JS_GetMethodById">JS_GetMethodById</a></li>
</ul>

<p>A SpiderMonkey extension allows a native function to return an lvalue—that is, a reference to a property of an object:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetCallReturnValue2" title="en/JS_SetCallReturnValue2">JS_SetCallReturnValue2</a></li>
</ul>

<p>A <code><a href="/en/SpiderMonkey/JSAPI_Reference/jsid" title="en/jsid">jsid</a></code> is kind of like a <code>jsval</code>, only different. A handful of APIs use <code>jsid</code>s instead of <code>jsval</code>s for property names: <code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JS_CheckAccess</a></code>, <code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Enumerate" title="en/JS_Enumerate">JS_Enumerate</a></code>, <code><a href="/En/JS_GetMethodById" title="en/JS_GetMethodById">JS_GetMethodById</a></code>, and <code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NextProperty" title="en/JS_NextProperty">JS_NextProperty</a></code>.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IdToValue" title="en/JS_IdToValue">JS_IdToValue</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_ValueToId" title="en/JS_ValueToId">JS_ValueToId</a></li>
 <li><a href="/en/JS_GetObjectId" title="en/JS_GetObjectId">JS_GetObjectId</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSIdArray" title="en/JSIdArray">JSIdArray</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DestroyIdArray" title="en/JS_DestroyIdArray">JS_DestroyIdArray</a></li>
</ul>

<p><code>jsid</code> constants:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_VOID" title="en/JSID_VOID">JSID_VOID</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_EMPTY" title="en/JSID_EMPTY">JSID_EMPTY</a></li>
</ul>

<p>Function and macros for checking the type of a <code>jsid</code>:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_VOID" title="en/JSID_IS_VOID">JSID_IS_VOID</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_INT" title="en/JSID_IS_INT">JSID_IS_INT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_STRING" title="en/JSID_IS_STRING">JSID_IS_STRING</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_OBJECT" title="en/JSID_IS_OBJECT">JSID_IS_OBJECT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_GCTHING" title="en/JSID_IS_GCTHING">JSID_IS_GCTHING</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_ZERO" title="en/JSID_IS_ZERO">JSID_IS_ZERO</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_EMPTY" title="en/JSID_IS_EMPTY">JSID_IS_EMPTY</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSID_IS_DEFAULT_XML_NAMESPACE" title="en/JSID_IS_DEFAULT_XML_NAMESPACE">JSID_IS_DEFAULT_XML_NAMESPACE</a></li>
</ul>

<h3 id="Classes" name="Classes">Classes</h3>

<p>These API features are used to define custom classes—object types that are implemented in C/C++ code but accessible from JavaScript.</p>

<ul>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass" title="en/SpiderMonkey/JSAPI_Reference/JSClass">JSClass</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSExtendedClass" title="en/SpiderMonkey/JSAPI_Reference/JSExtendedClass">JSExtendedClass</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps">JSObjectOps</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSXMLObjectOps" title="en/SpiderMonkey/JSAPI_Reference/JSXMLObjectOps">JSXMLObjectOps</a></li>
 <li>struct <a href="/En/SpiderMonkey/JSAPI_Reference/JSFunctionSpec" title="En/SpiderMonkey/JSAPI_Reference/JSFunctionSpec">JSFunctionSpec</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSProperty" title="en/SpiderMonkey/JSAPI_Reference/JSProperty">JSProperty</a></li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSPropertySpec" title="en/SpiderMonkey/JSAPI_Reference/JSPropertySpec">JSPropertySpec</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_InitClass" title="en/SpiderMonkey/JSAPI_Reference/JS_InitClass">JS_InitClass</a></li>
</ul>

<p>Adding native properties and methods to classes:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSNative" title="en/SpiderMonkey/JSAPI_Reference/JSNative">JSNative</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JSFastNative</a> {{ jsapi_minversion_inline("1.8") }}</li>
 <li>struct <a href="/En/SpiderMonkey/JSAPI_Reference/JSFunctionSpec" title="En/SpiderMonkey/JSAPI_Reference/JSFunctionSpec">JSFunctionSpec</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_FS" title="en/JS_FS">JS_FS</a> {{ jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_FS" title="en/JS_FN">JS_FN</a> {{ jsapi_minversion_inline("1.8") }}</li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_FS" title="en/JS_FS_END">JS_FS_END</a> {{ jsapi_minversion_inline("1.8") }}</li>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSPropertySpec" title="en/SpiderMonkey/JSAPI_Reference/JSPropertySpec">JSPropertySpec</a></li>
</ul>

<p><code>JSFastNative</code> methods use these macros: {{ jsapi_minversion_inline("1.8") }}</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_CALLEE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_THIS</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_THIS_OBJECT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_ARGV</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_RVAL</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/SpiderMonkey/JSAPI_Reference/JSFastNative">JS_SET_RVAL</a></li>
</ul>

<p>The behavior of a <code>JSClass</code> and its instances can be customized in many ways using callback functions.</p>

<p><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass" title="en/SpiderMonkey/JSAPI_Reference/JSClass">JSClass</a> method types:</p>

<ul>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JSPropertyOp" title="En/SpiderMonkey/JSAPI_Reference/JSPropertyOp">JSPropertyOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSEnumerateOp" title="en/SpiderMonkey/JSAPI_Reference/JSEnumerateOp">JSEnumerateOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.enumerate" title="en/SpiderMonkey/JSAPI_Reference/JSClass.enumerate">JSNewEnumerateOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.resolve" title="en/SpiderMonkey/JSAPI_Reference/JSClass.resolve">JSResolveOp</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSNewResolveOp</a> – <a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSRESOLVE_ASSIGNING</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSRESOLVE_CLASSNAME</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSRESOLVE_DECLARING</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSRESOLVE_DETECTING</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp" title="En/SpiderMonkey/JSAPI_Reference/JSNewResolveOp">JSRESOLVE_QUALIFIED</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defaultValue" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defaultValue">JSConvertOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.finalize" title="en/SpiderMonkey/JSAPI_Reference/JSClass.finalize">JSFinalizeOp</a></li>
 <li><a href="/en/JSClass.getObjectOps" title="en/JSClass.getObjectOps">JSGetObjectOps</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.checkAccess" title="en/SpiderMonkey/JSAPI_Reference/JSClass.checkAccess">JSCheckAccessOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.xdrObject" title="en/SpiderMonkey/JSAPI_Reference/JSClass.xdrObject">JSXDRObjectOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.hasInstance" title="en/SpiderMonkey/JSAPI_Reference/JSClass.hasInstance">JSHasInstanceOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.mark" title="en/SpiderMonkey/JSAPI_Reference/JSClass.mark">JSMarkOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSTraceOp" title="en/SpiderMonkey/JSAPI_Reference/JSTraceOp">JSTraceOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.reserveSlots" title="en/SpiderMonkey/JSAPI_Reference/JSClass.reserveSlots">JSReserveSlotsOp</a></li>
</ul>

<p><a href="/en/SpiderMonkey/JSAPI_Reference/JSExtendedClass" title="en/SpiderMonkey/JSAPI_Reference/JSExtendedClass">JSExtendedClass</a> method types:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSExtendedClass.iteratorObject" title="en/SpiderMonkey/JSAPI_Reference/JSExtendedClass.iteratorObject">JSIteratorOp</a></li>
 <li><a href="/en/JSEqualityOp" title="en/JSEqualityOp">JSEqualityOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOp" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOp">JSObjectOp</a></li>
</ul>

<p><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps">JSObjectOps</a> method types:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.newObjectMap" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.newObjectMap">JSNewObjectMapOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.destroyObjectMap" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.destroyObjectMap">JSObjectMapOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.lookupProperty" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.lookupProperty">JSLookupPropOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defineProperty" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defineProperty">JSDefinePropOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getProperty" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getProperty">JSPropertyIdOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getAttributes" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getAttributes">JSAttributesOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defaultValue" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.defaultValue">JSConvertOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.enumerate" title="en/SpiderMonkey/JSAPI_Reference/JSClass.enumerate">JSNewEnumerateOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.checkAccess" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.checkAccess">JSCheckAccessIdOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOp" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOp">JSObjectOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.dropProperty" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.dropProperty">JSPropertyRefOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.xdrObject" title="en/SpiderMonkey/JSAPI_Reference/JSClass.xdrObject">JSXDRObjectOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.hasInstance" title="en/SpiderMonkey/JSAPI_Reference/JSClass.hasInstance">JSHasInstanceOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.setProto" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.setProto">JSSetObjectSlotOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSTraceOp" title="en/SpiderMonkey/JSAPI_Reference/JSTraceOp">JSTraceOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.finalize" title="en/SpiderMonkey/JSAPI_Reference/JSClass.finalize">JSFinalizeOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getRequiredSlot" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getRequiredSlot">JSGetRequiredSlotOp</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getRequiredSlot" title="en/SpiderMonkey/JSAPI_Reference/JSObjectOps.getRequiredSlot">JSSetRequiredSlotOp</a></li>
</ul>

<p><a href="/en/SpiderMonkey/JSAPI_Reference/JSXMLObjectOps" title="en/SpiderMonkey/JSAPI_Reference/JSXMLObjectOps">JSXMLObjectOps</a> method types:</p>

<ul>
 <li><a href="/en/JSGetMethodOp" title="en/JSGetMethodOp">JSGetMethodOp</a></li>
 <li><a href="/en/JSSetMethodOp" title="en/JSSetMethodOp">JSSetMethodOp</a></li>
 <li><a href="/en/JSEnumerateValuesOp" title="en/JSEnumerateValuesOp">JSEnumerateValuesOp</a></li>
 <li><a href="/en/JSEqualityOp" title="en/JSEqualityOp">JSEqualityOp</a></li>
 <li><a href="/en/JSConcatenateOp" title="en/JSConcatenateOp">JSConcatenateOp</a></li>
</ul>

<p>These stub functions can be used when creating a custom <code>JSClass</code>:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub" title="en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub">JS_ConvertStub</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub" title="en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub">JS_EnumerateStub</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub" title="en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub">JS_FinalizeStub</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub" title="en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub">JS_PropertyStub</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub" title="en/SpiderMonkey/JSAPI_Reference/JS_PropertyStub">JS_ResolveStub</a></li>
</ul>

<p>The behavior of a <code>JSClass</code> can be customized using these flags:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSClass.flags</a> – <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_CONSTUCT_PROTOTYPE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_GLOBAL_FLAGS</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_HAS_PRIVATE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_HAS_RESERVED_SLOTS</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_IS_EXTENDED</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_MARK_IS_TRACE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_NEW_ENUMERATE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_NEW_RESOLVE</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_NEW_RESOLVE_GETS_START</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_PRIVATE_IS_NSISUPPORTS</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.flags" title="en/SpiderMonkey/JSAPI_Reference/JSClass.flags">JSCLASS_SHARE_ALL_PROPERTIES</a></li>
</ul>

<h3 id="Arrays" name="Arrays">Arrays</h3>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewArrayObject" title="en/JS_NewArrayObject">JS_NewArrayObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_IsArrayObject" title="en/JS_IsArrayObject">JS_IsArrayObject</a></li>
</ul>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_HasArrayLength" title="en/JS_HasArrayLength">JS_HasArrayLength</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetArrayLength" title="en/JS_GetArrayLength">JS_GetArrayLength</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetArrayLength" title="en/JS_SetArrayLength">JS_SetArrayLength</a></li>
</ul>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AliasElement" title="en/JS_AliasElement">JS_AliasElement</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineElement" title="en/JS_DefineElement">JS_DefineElement</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteElement" title="en/JS_DeleteElement">JS_DeleteElement</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DeleteElement2" title="en/JS_DeleteElement2">JS_DeleteElement2</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetElement" title="en/JS_GetElement">JS_GetElement</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_LookupElement" title="en/JS_LookupElement">JS_LookupElement</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetElement" title="en/JS_SetElement">JS_SetElement</a></li>
</ul>

<h3 id="Functions" name="Functions">Functions</h3>

<p>Calling a function or a method of an object:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CallFunction" title="en/JS_CallFunction">JS_CallFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CallFunctionName" title="en/JS_CallFunctionName">JS_CallFunctionName</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CallFunctionValue" title="en/JS_CallFunctionValue">JS_CallFunctionValue</a></li>
</ul>

<p>Function accessors:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ObjectIsFunction" title="en/JS_ObjectIsFunction">JS_ObjectIsFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetFunctionArity" title="en/JS_GetFunctionArity">JS_GetFunctionArity</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetFunctionFlags" title="en/SpiderMonkey/JSAPI Reference/JS GetFunctionFlags">JS_GetFunctionFlags</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetFunctionId" title="en/JS_GetFunctionId">JS_GetFunctionId</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetFunctionName" title="en/JS_GetFunctionName">JS_GetFunctionName</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetFunctionObject" title="en/JS_GetFunctionObject">JS_GetFunctionObject</a></li>
</ul>

<p>Creating functions:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CloneFunctionObject" title="en/JS_CloneFunctionObject">JS_CloneFunctionObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineFunction" title="en/JS_DefineFunction">JS_DefineFunction</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineFunction" title="en/JS_DefineFunction">JS_DefineUCFunction</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_DefineFunctions" title="en/JS_DefineFunctions">JS_DefineFunctions</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_NewFunction" title="en/JS_NewFunction">JS_NewFunction</a></li>
</ul>

<h3 id="RegExps" name="RegExps">RegExps</h3>

<ul>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject" title="En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject">JS_NewRegExpObject</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject" title="En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject">JS_NewUCRegExpObject</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetRegExpInput" title="en/SpiderMonkey/JSAPI_Reference/JS_SetRegExpInput">JS_SetRegExpInput</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearRegExpRoots" title="en/SpiderMonkey/JSAPI_Reference/JS_ClearRegExpRoots">JS_ClearRegExpRoots</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearRegExpStatics" title="en/SpiderMonkey/JSAPI_Reference/JS_ClearRegExpStatics">JS_ClearRegExpStatics</a></li>
</ul>

<h3 id="Security" name="Security">Serialization</h3>

<ul>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSStructuredCloneCallbacks" title="en/SpiderMonkey/JSAPI_Reference/JSStructuredCloneCallbacks">JSStructuredCloneCallbacks</a>, JS_SetStructuredCloneCallbacks</li>
 <li>JS_ReadStructuredClone, JS_WriteStructuredClone</li>
 <li>JS_StructuredClone</li>
 <li>JS_ReadUint32Pair, JS_ReadBytes, JS_WriteUint32Pair, JS_WriteBytes</li>
</ul>

<h3 id="Security" name="Security">Security</h3>

<ul>
 <li>struct <a href="/en/SpiderMonkey/JSAPI_Reference/JSPrincipals" title="en/JSPrincipals">JSPrincipals</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSPRINCIPALS_HOLD" title="en/JSPRINCIPALS_HOLD">JSPRINCIPALS_HOLD</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JSPRINCIPALS_HOLD" title="en/JSPRINCIPALS_HOLD">JSPRINCIPALS_DROP</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetObjectPrincipalsFinder" title="en/JS_SetObjectPrincipalsFinder">JS_SetObjectPrincipalsFinder</a> <span class="inlineIndicator standardNote">JSAPI 1.8 and earlier</span></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPrincipalsTranscoder" title="en/JS_SetPrincipalsTranscoder">JS_SetPrincipalsTranscoder</a> <span class="inlineIndicator standardNote">JSAPI 1.8 and earlier</span></li>
</ul>

<ul>
 <li>enum <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSAccessMode</a> – <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_PROTO</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_PARENT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_IMPORT</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_WATCH</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_READ</a>, <a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JSACC_WRITE</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_CheckAccess" title="en/JS_CheckAccess">JS_CheckAccess</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSObjectOps.checkAccess" title="en/JSObjectOps.checkAccess">JSObjectOps.checkAccess</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSClass.checkAccess" title="en/JSClass.checkAccess">JSClass.checkAccess</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetCheckObjectAccessCallback" title="en/JS_SetCheckObjectAccessCallback">JS_SetCheckObjectAccessCallback</a> <span class="inlineIndicator standardNote">JSAPI 1.8 and earlier</span></li>
</ul>

<p>{{ jsapi_minversion_inline("1.8.1") }} Security callbacks can be set per-runtime or per-context.</p>

<ul>
 <li><a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetSecurityCallbacks" title="En/SpiderMonkey/JSAPI Reference/JS GetSecurityCallbacks">JS_GetSecurityCallbacks</a>, <a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetSecurityCallbacks" title="En/SpiderMonkey/JSAPI Reference/JS GetSecurityCallbacks">JS_SetContextSecurityCallbacks</a>, <a class="internal" href="/En/SpiderMonkey/JSAPI_Reference/JS_GetSecurityCallbacks" title="En/SpiderMonkey/JSAPI Reference/JS GetSecurityCallbacks">JS_GetRuntimeSecurityCallbacks</a>, <a href="/En/SpiderMonkey/JSAPI_Reference/JS_GetSecurityCallbacks" title="En/SpiderMonkey/JSAPI_Reference/JS_GetSecurityCallbacks">JS_SetRuntimeSecurityCallbacks</a></li>
</ul>

<h3 id="Threading" name="Threading">Threading</h3>

<p>The following functions support the SpiderMonkey threading model.</p>

<p><strong>Note:</strong> JS_THREADSAFE is now permanently on.</p>

<p><span class="inlineIndicator standardNote">JSAPI 1.7 and earlier</span> They are only available in <code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_THREADSAFE" title="en/JS_THREADSAFE">JS_THREADSAFE</a></code> builds.</p>

<p>{{ jsapi_minversion_inline("1.8") }} These functions are always available, but in non-<code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_THREADSAFE" title="en/JS_THREADSAFE">JS_THREADSAFE</a></code> builds, they do nothing.</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_BeginRequest" title="en/JS_BeginRequest">JS_BeginRequest</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_BeginRequest" title="en/JS_BeginRequest">JS_EndRequest</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_YieldRequest" title="en/JS_YieldRequest">JS_YieldRequest</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SuspendRequest" title="en/JS_SuspendRequest">JS_SuspendRequest</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SuspendRequest" title="en/JS_SuspendRequest">JS_ResumeRequest</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetContextThread" title="en/JS_GetContextThread">JS_GetContextThread</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearContextThread" title="en/JS_ClearContextThread">JS_SetContextThread</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ClearContextThread" title="en/JS_ClearContextThread">JS_ClearContextThread</a></li>
</ul>

<p>The following functions are always available, but in non-<code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_THREADSAFE" title="en/JS_THREADSAFE">JS_THREADSAFE</a></code> builds, they do nothing:</p>

<ul>
 <li><a href="/en/JS_LockRuntime" title="en/JS_LockRuntime">JS_LockRuntime</a></li>
 <li><a href="/en/JS_UnlockRuntime" title="en/JS_UnlockRuntime">JS_UnlockRuntime</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Lock" title="en/JS_Lock">JS_Lock</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_Unlock" title="en/JS_Unlock">JS_Unlock</a> {{ Deprecated_inline() }}</li>
</ul>

<h3 id="Time" name="Time">Time</h3>

<ul>
 <li><a href="/en/JS_Now" title="en/JS_Now">JS_Now</a></li>
</ul>

<h3 id="Callback_Types" name="Callback_Types">Callback Types</h3>

<p>Native function types:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSNative" title="en/JSNative">JSNative</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFastNative" title="en/JSFastNative">JSFastNative</a></li>
</ul>

<p>Other callback types:</p>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddExternalStringFinalizer" title="en/JS_AddExternalStringFinalizer">JSStringFinalizeOp</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddExternalStringFinalizer" title="en/JS_AddExternalStringFinalizer">JS_AddExternalStringFinalizer</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_TRACER_INIT" title="en/JS_TRACER_INIT">JSTraceCallback</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_TRACER_INIT" title="en/JS_TRACER_INIT">JS_TRACER_INIT</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SET_TRACING_DETAILS" title="en/JS_SET_TRACING_DETAILS">JSTraceNamePrinter</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SET_TRACING_DETAILS" title="en/JS_SET_TRACING_DETAILS">JS_SET_TRACING_DETAILS</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetContextCallback" title="en/JS_SetContextCallback">JSContextCallback</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetContextCallback" title="en/JS_SetContextCallback">JS_SetContextCallback</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JSGCCallback</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetGCCallback" title="en/JS_SetGCCallback">JS_SetGCCallback</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetExtraGCRoots" title="en/JS_SetExtraGCRoots">JSTraceDataOp</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetExtraGCRoots" title="en/JS_SetExtraGCRoots">JS_SetExtraGCRoots</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetBranchCallback" title="en/JS_SetBranchCallback">JSBranchCallback</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetBranchCallback" title="en/JS_SetBranchCallback">JS_SetBranchCallback</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetErrorReporter" title="en/JS_SetErrorReporter">JSErrorReporter</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetErrorReporter" title="en/JS_SetErrorReporter">JS_SetErrorReporter</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JSErrorCallback</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_ReportErrorNumber" title="en/JS_ReportErrorNumber">JS_ReportErrorNumber</a> and friends</li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddArgumentFormatter" title="en/JS_AddArgumentFormatter">JSArgumentFormatter</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_AddArgumentFormatter" title="en/JS_AddArgumentFormatter">JS_AddArgumentFormatter</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPrincipalsTranscoder" title="en/JS_SetPrincipalsTranscoder">JSPrincipalsTranscoder</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetPrincipalsTranscoder" title="en/JS_SetPrincipalsTranscoder">JS_SetPrincipalsTranscoder</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetObjectPrincipalsFinder" title="en/JS_SetObjectPrincipalsFinder">JSObjectPrincipalsFinder</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetObjectPrincipalsFinder" title="en/JS_SetObjectPrincipalsFinder">JS_SetObjectPrincipalsFinder</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MapGCRoots">JSGCRootMapFun</a> - used by <a href="/en/SpiderMonkey/JSAPI_Reference/JS_MapGCRoots" title="en/JS_MapGCRoots">JS_MapGCRoots</a></li>
 <li><code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetFunctionCallback#Callback_syntax" title="en/SpiderMonkey/JSAPI Reference/JS SetFunctionCallback#Callback syntax">JSFunctionCallback</a></code> - used by <code><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetFunctionCallback" title="en/SpiderMonkey/JSAPI Reference/JS SetFunctionCallback">JS_SetFunctionCallback()</a></code></li>
</ul>

<p>See also <a href="#Classes">Classes</a>, above.</p>

<h3 id="Macros" name="Macros">Macros</h3>

<ul>
 <li><a href="/en/JS_DEFAULT_XML_NAMESPACE_ID" title="en/JS_DEFAULT_XML_NAMESPACE_ID">JS_DEFAULT_XML_NAMESPACE_ID</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFUN_BOUND_METHOD" title="en/JSFUN_BOUND_METHOD">JSFUN_BOUND_METHOD</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/JSFUN_GETTER" title="en/JSFUN_GETTER">JSFUN_GETTER</a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JSFUN_GLOBAL_PARENT" title="en/JSFUN_GLOBAL_PARENT">JSFUN_GLOBAL_PARENT</a> {{ Deprecated_inline() }}</li>
 <li><a href="/en/JSFUN_HEAVYWEIGHT" title="en/JSFUN_HEAVYWEIGHT">JSFUN_HEAVYWEIGHT</a></li>
 <li><a href="/en/JSFUN_LAMBDA" title="en/JSFUN_LAMBDA">JSFUN_LAMBDA</a></li>
 <li><a href="/en/JSFUN_SETTER" title="en/JSFUN_SETTER">JSFUN_SETTER</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject" title="en/JSREG_GLOB">JSREG_GLOB</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject" title="en/JSREG_FOLD">JSREG_FOLD</a></li>
 <li><a href="/En/SpiderMonkey/JSAPI_Reference/JS_NewRegExpObject" title="en/JSREG_MULTILINE">JSREG_MULTILINE</a></li>
</ul>

<h3 id="C.2B.2B_features" name="C.2B.2B_features">C++ features</h3>

<ul>
 <li>class <a href="/en/JSAutoRequest" title="en/JSAutoRequest">JSAutoRequest</a></li>
 <li>class <a href="/en/JSAutoLocalRootScope" title="en/JSAutoLocalRootScope">JSAutoLocalRootScope</a></li>
 <li>class <a href="/en/Performance/JS::PerfMeasurement" title="en/JS::PerfMeasurement">JS::PerfMeasurement</a> (in <code>jsperf.h</code>)</li>
</ul>

<h3 id="Tracing_and_debugging">Tracing and debugging</h3>

<ul>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_SetFunctionCallback" title="en/SpiderMonkey/JSAPI Reference/JS SetFunctionCallback"><code>JS_SetFunctionCallback()</code></a></li>
 <li><a href="/en/SpiderMonkey/JSAPI_Reference/JS_GetFunctionCallback" title="en/SpiderMonkey/JSAPI Reference/JS GetFunctionCallback"><code>JS_GetFunctionCallback()</code></a></li>
</ul>