What is Delegates ? Explanation with simple example.

      This is the most powerful  and exciting new feature of c# or c sharp. This concept , the core of object oriented programming , allows you to worry more about the flow of the system at lowest level, without worrying about the specifics of individual tasks that will be handled.

    What does delegate means? In UK,USA  ,people elect their  delegates to represent their legislature or council. These Delegates represent the entire nation or state because it is impossible if the entire populations were to present to represent countries. In short ,you can say delegates is like as  function pointer  in c or c++.

What is Function pointer?

Function pointer is pointer .i.e variable , which point to the address to the function.

In other word we define delegates  “ it allows us to reference of method.”

Types Of Delegates:

There are two types of delegates:-

1.)Single cast delegates

2.)Multiple cast delegates

Syntax of Delegate:

1.)Single cast delegates:

public  Delegate <return  type>   <delegate_name>(parameters)

2.)Multiple cast delegates:

public Delegate void  <delegate_name >(parameters)

Example:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Delegate

{

    public delegate int Delg(int x,int y);

    public class Math

    {

        public static int Add(int x,int y)

        {

            return x + y;

        }

        public static int Mul(int x,int y)

        {

            return x * y;

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            Delg  del = new Delg(Math.Add );

            int add = del(7,7);

            Console.WriteLine(add);

            Delg del1 = new Delg(Math .Mul );

            int mul1 = del1(5,6);

            Console.WriteLine(mul1);

            Console.ReadLine();

        }

    }

}

Advantages of Delegates:

Dynamic binding can be done by using delegate because we can call more than one method at a time dynamically by calling the delegate in which method is defined.

Static delegate is used for delegate  without  creating a local delegate instant. Just pass in the static delegate of class.

Disadvantage of delegate:

The problem with static delegate that it must be instantiated whether they are in use or not.