This article covers features introduced in SpiderMonkey 1.8.5

Query [[Extensible]] properly of the given object.


JS_IsExtensible(JSContext *cx, JS::HandleObject obj, bool *extensible);
Name Type Description
cx JSContext * The context. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext.
obj JS::HandleObject The object to examine.
extensible bool * Out parameter. Receives true if extensible, false otherwise.


JS_IsExtensible queries [[Extensible]] property of the specified object, obj.

If successful, JS_IsExtensible stores [[Extensible]] property to *extensible and returns true, otherwise returns false and the value of *extensible is undefined.

See also