Obsolete since JSAPI 8
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
Determines if an object has an array length property.
Syntax
JSBool JS_HasArrayLength(JSContext *cx, JSObject *obj, jsuint *lengthp);
Name | Type | Description |
---|---|---|
cx |
JSContext * |
Pointer to a JS context from which to derive runtime information. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext . |
obj |
JSObject * |
Array object to get the length of. |
lengthp |
jsuint * |
Out parameter. On success, *lengthp receives the length of the array. |
Description
JS_HasArrayLength
determines if an object, obj
, has a length
property. If the property exists, JS_HasArrayLength
stores the current value of the property in *lengthp
.
On success, JS_HasArrayLength
returns JS_TRUE
, and *lengthp
receives the current value of the length
property. On failure, JS_HasArrayLength
returns JS_FALSE
, and the value left in *lengthp
is undefined.
This function differs from JS_GetArrayLength
in the treatment of errors and unusual cases, like when an object's length
is negative or not a number. This function may return JS_FALSE
without having reported any error or exception.