Obsolete since JavaScript 1.8.5
This feature is obsolete.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.

JSReserveSlotsOp is the type of the JSClass.reserveSlots.


typedef uint32
(* JSReserveSlotsOp)(JSContext *cx, JSObject *obj);
Name Type Description
cx JSContext * The JS context in which the new object is being created.
obj JSObject * The new object.


Warning: JSAPI applications should not use this hook. A class cannot freely use a reserveSlots hook to reserve a different number of slots for each object. Rather, within a JSRuntime, every call to the same reserveSlots hook must return the same value (excepting a few internal classes such as Function, Call, and Block).

JSClass hooks

JSClass offers the following hook:

See Also