Extension Methods in C#

Introduction

 

Today, in this article let's play around with one of the interesting and most useful concept in C#.

Question: What are extension methods?

In simple terms "Extension methods are a special kind of static method, but they are called as if they were instance methods on the extended type."

Step 1: Create a new console application

 

 

Step 2: The complete code of Arithmetic.cs looks like this

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ExtensionMethodsApp

{

    public static class Arithmetic

    {

        public static double Add(this double a, double b)

        {

            return a + b;

        }

        public static double Sub(this double a, double b)

        {

            return a - b;

        }

        public static double Mul(this double a, double b)

        {

            return a * b;

        }

        public static double Div(this double a, double b)

        {

            return a / b;

        }

    }

}

 

 

Step 3: The extension methods showing in intellisense looks like this

Step 4: The complete code of Program.cs looks like this

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ExtensionMethodsApp

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("Addition Result is: " + Arithmetic.Add(2, 2));

            Console.WriteLine("Substraction Result is: " + Arithmetic.Sub(2, 1));

            Console.WriteLine("Multiplication Result is: " + Arithmetic.Mul(2, 5));

            Console.WriteLine("Division Result is: " + Arithmetic.Div(2, 12));

            Console.ReadKey(true);

        }

    }

}

 

Step 5: The output of the application looks like this

 

 

I hope this article is useful for you.