Question

In unit 6 we are introduced to the concept of polymorphism which is derived from the Greek words poly, which means many and morpheus, which means form, structure. Discuss polymorphism in objective oriented programming and provide a java example that details the implementation of polymorphism in java objects.

Answer 1

Polymorphism is the property of a function to have more than one forms. It can be of two types:

1. Compile Time Polymorphism : It can be achieved by
   • Function Overloading : Achieved when there are more than 1 fucntions with same name but with different arguments.
   • Operator Overloading : When the operators are overloaded for a class.
2. Run Time Polymorphism : It can be achieved by Function Overriding. It is when a function of the suer class is also defined in the class inheriting the super class.

Sample Code ( Function Overriding )

class A

{

    public void fxn()

    {

        System.out.println("Base Class.");

    }

}

class B extends A

{

    // overriden function

    public void fxn()

    {

        System.out.println("Derived Class.");

    }

}

public class Solution

{

    public static void main(String[] args)

    {

         //object of parent class

        A ob1 = new A();

        //object of child class

        B ob2 = new B();

        // fxn() in class A is executed

        ob1.fxn();

        // the overriden function in class B is executed

        ob2.fxn();

    }

}

Sample Output

Base Class Derived class