isKindOf

The isKindOf condition method of the Object class returns true if the receiver is an instance of the class specified in the classObject parameter or any of its subclasses, or it returns false if the receiver is not an instance.

An error 4 (Object not found) is not raised if the instance id of the receiver is invalid. In earlier releases the hasInstance method of the Class class was implemented to allow the type of an invalid object to be determined. This method is now defined only for upward compatibility. Similarly, error 1090 (Attempted access via null object reference) is not raised if the receiver is null.