This feature is obsolete.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.
Determine whether a given
jsval is an object or null.
JSBool JSVAL_IS_OBJECT(jsval v);
JSVAL_IS_OBJECT(v) returns true if
v is either an object or
JSVAL_NULL. This indicates that it is safe to call
JSVAL_TO_OBJECT(v) to convert
v to type
JSObject *. If v is a string, number, boolean, or undefined, the result is false.