Test whether a given object is a Function.
Syntax
bool JS_ObjectIsFunction(JSContext *cx, JSObject *obj);
| Name | Type | Description | 
|---|---|---|
| cx | JSContext * | A context. | 
| obj | JSObject * | The object to test. This must not be NULL. | 
Description
JS_ObjectIsFunction tests whether obj is a function object (faster than comparing obj's class name to Function, but equivalent unless someone has overwritten the Function identifier with a different constructor and then created instances using that constructor that might be passed in as obj).
JS_ObjectIsFunction returns true if obj is a Function and false otherwise.
If JS_ObjectIsFunction returns true, JS_ValueToFunction will always return non-null. JS_ObjectIsFunction always succeeds. Note that the result may be false even for some callable objects, such as regular expression objects or proxy objects