using System;

​

public delegate void Calculation( int a, int b); // delegate declaration

​

​

​

public class Program

{

    public static  void addition( int a, int b)

    {

        int result = a+b;

        Console.WriteLine(" addition result is : {0}" , result );

    }

    public static  void subtraction( int a, int b)

    {

        int result = a-b;

        Console.WriteLine(" subtraction result is : {0}" , result );

    }

    public static  void multiplication( int a, int b)

    {

        int result = a*b;

        Console.WriteLine(" multiplication result is : {0}" , result );

    }

    public static  void division( int a, int b)

    {

        int result = a/b;

        Console.WriteLine(" division result is : {0}" , result );

    }

​

    public static void Main()

    {

        Calculation obj = new Calculation(Program.subtraction);

        obj.Invoke(20,30);  // one way using invoke method

        obj= addition;   //other way is point to different methodsc

        obj( 30,40);

        Calculation obj1 = new Calculation(Program.division); // create different object and use first method

        obj1.Invoke(30,5); 

        obj = multiplication;

        obj(34,45);

    }

}