What is polymorphism

In a programming language that exhibits polymorphism, objects of classes belonging to the same hierarchical tree (inherited from a common base class) may possess functions bearing the same name, but each having different behaviors.

As an example, assume there is a base class named Animals from which the subclasses Horse, Fish and Bird are derived. Also assume that the Animals class has a function named Move, which is inherited by all subclasses mentioned. With polymorphism, each subclass may have its own way of implementing the function. So, for example, when the Move function is called in an object of the Horse class, the function might respond by displaying trotting on the screen. On the other hand, when the same function is called in an object of the Fish class, swimming might be displayed on the screen. In the case of a Bird object, it may be flying.

• It allows you to invoke methods of derived class through base class reference during runtime.
• It has the ability for classes to provide different implementations of methods that are called through the same name.

1. Compile time polymorphism/Overloading
2. Runtime polymorphism/Overriding