What Is Polymorphism?
Polymorphism refers to the ability of an object to respond in a logically identical fashion to messages of the same protocol, containing differing types of objects. Consider 1 + 5 and 1 + 5.1. In the former, the message “+ 5” is sent to an object of class integer (1). In the later, the message “+ 5.1” is sent to the same integer object. The form of the message (its protocol) is identical in both cases. What differs is the type of object on the right-hand side of these messages. The former is an integer object (5) while the later is a floating point object (5.1). The receiver (1) appears (to other objects) to respond in the same way to both messages. Internally, however, it knows that it must treat the two types of objects differently in order to obtain the same overall respons