Polymorphism, Method overloading and Method Overriding

 Introduction of Polymorphism

    Polymorphism is the concept by which we can perform single action/operation in different ways. In other word ability to tae more than one form called polymorphism.

    Polymorphism plays an important role in allowing objects having different internal structure to share same external interface. That means the general class of operation may be access in same manner but the specified action with each operation may be different. Ploymorphism is use in implementing inheritance. There are two types of polymorphism in java those are as follows:

1. Compile-time polymorphism.
2. Runtime polymorphism.

    We can perform polymorphism using method overloading and method overrding.

1. Compile-time polymorphism:

    We can achive the compile time polymorphism using function/method overloading concept. When there are multiple function with the same name but having different parameter list or parameter then it is called function/method overloading. We can overload a function/method by changing parameter list or type of parameter. For example,

class MultiplyFun { 

// Method with 2 parameter 

static int Multiply(int a, int b) 

{ 

return a * b; 

} 

// Method with the same name but 3 parameter 

static int Multiply(int a, int b, int c) 

{ 

return a * b * c; 

} 

} 

class Main { 

public static void main(String[] args) 

{ 

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

System.out.println(MultiplyFun.Multiply(2, 7, 3)); 

} 

} 

OUTPUT:

8
42

2. Runtime polymorphism:

    We can achive the runtime ploymorphism using funtion/method overriding. If a subclass provide specific implementation of method which is already declare in sperclass then it is called as function/method overriding. In method overriding the method name and the parameter list is same. For example,

class Vehicle{

  void run(){System.out.println("Vehicle is running");}

  }

  class Bike2 extends Vehicle{

  void run(){System.out.println("Bike is running safely");}

  public static void main(String args[]){

  Bike2 obj = new Bike2();

  obj.run();

  }

}

Output:

Bike is running safely