JSAPI method equivalent to the instanceof operator in JavaScript.
Syntax
bool JS_HasInstance(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<JS::Value> v, bool *bp);
| 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 |
JS::Handle<JSObject*> |
Constructor/prototype to test. |
v |
JS::Handle<JS::Value> |
The value to test. |
bp |
bool * |
Out parameter. On success, *bp receives the result of the test. |
Description
JS_HasInstance determines if a specified JS value, vobj. This function is equivalent to v instanceof obj test in JavaScript. On success, JS_HasInstance stores the result of the instanceof test in *bp and returns true. On error or exception, it returns false, and the value left in *bp is undefined.
When providing a prototype as obj, the prototype's JSClass must have its hasInstance method set. Otherwise JS_HasInstance returns false.