Polymorphism in Java-Part 1

The concept by which we can perform a single action in different ways is polymorphism. It means that polymorphism allows you to define one interface and have multiple implementations.  Polymorphism can be performed in java by method overloading and method overriding.

The two types of polymorphism in Java are:

1. Compile-time polymorphism
2. Run-time polymorphism

Compile time polymorphism

It is also called as static polymorphism. Function overloading or operator overloading is used to achieve this type of polymorphism.

Method Overloading: Multiple functions having same name, but different parameters then are said to be overloaded. These functions can be overloaded by change in number of arguments or change in type of arguments.

//Java program for Method overloading

  

class MultiplyFun {

  

    // Method with 2 parameter

    static int Multiply(int a, int b)

    {

        return a * b;

    }

  

    // Same name but 2 double parameter

    static double Multiply(double a, double b)

    {

        return a * b;

    }

}

  

class Main {

    public static void main(String[] args)

    {

  

        System.out.println(MultiplyFun.Multiply(2, 4));

  

        System.out.println(MultiplyFun.Multiply(5.5, 6.3));

    }

}

Output: 8,34.6

Runtime Polymorphism

It is also called as Dynamic Method Dispatch. In this process the function call to the overridden method is resolved at runtime. Method overriding is used to achieve this type of polymorphism.

// Java program for Method overriding class Parent {        void Print()     {         System.out.println("parent class");     } }    class subclass1 extends Parent {        void Print()     {         System.out.println("subclass1");     } }    class subclass2 extends Parent {        void Print()     {         System.out.println("subclass2");     } }    class TestPolymorphism3 {     public static void main(String[] args)     {            Parent a;            a = new subclass1();         a.Print();            a = new subclass2();         a.Print();     } }

Output: subclass1

subclass2

Rishita Jaiswal
K-28