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    JS_GetArrayLength

    Retrieve the number of elements in an array object.

    Syntax

    bool
    JS_GetArrayLength(JSContext *cx, JS::Handle<JSObject*> obj,
                      uint32_t *lengthp);
    
    Name Type Description
    cx JSContext * The context in which to look up the array's length. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext.
    obj JS::Handle<JSObject*> The object to examine.
    lengthp uint32_t * Out parameter. On success, *lengthp receives the length of the array.

    Description

    JS_GetArrayLength gets the .length property of obj as though by calling JS_GetProperty and converts it to a 32-bit unsigned integer. If obj is an array (see JS_IsArrayObject), this is guaranteed to succeed, because the .length property of an array is always a number and can't be deleted or redefined.

    On success, JS_GetArrayLength stores the length in *lengthp and returns true. On failure, it reports an error and returns false, and the value left in *lengthp is undefined.

    See Also

    Document Tags and Contributors

    Contributors to this page: evilpie, fscholz, Nickolay, Callek, Crowder, MMondor, Tservo, arai, Dria, Jorend
    Last updated by: arai,
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