private static readonly MethodInfo ExtensionMethod = 

  typeof(ObjectExtensions).GetMethod(nameof(ObjectExtensions.NewMethod));

/*

-Extension methods are methods that can be inserted into existing types without creating a new derived type, recompiling,

or otherwise modifying the original type.

-Extension methods are static methods, but in C# they are called as if they were normal C# methods.

They use this modifier in their parameters.

-C# already includes a LINQ library extension method based on the IEnumerable interface, and any class that inherits from this interface, such as an array or list.

But if you want to add a new function to any data type, you should make a static class and add any static method as an extension method.

*/

//EX We want to add a print method that can print any type of array.

​

//First step to create static class

​

public static class Extensiton {

  //create your function =should be static, and this keyword must precede the method parameter.

  public static void Print < T > (this T[] array) {

    foreach(var item in array) {

      Console.WriteLine(item);

    }

  }

}

​

//calling Fucntion 

​

public class Program {

  static void Main(string[] args) {

    var numbers = new int[] {

      1,

      2,

      3,

      4,

      5

    };

    var fruits = new [] {

      "orange",

      "banana",

      "lemon",

      "grabs"

    };

    //print numbers

    numbers.Print(); // 1 2 3 4 5

    //print fruits

    fruits.Print(); // orange banana lemon grabs

​

    //notice this keyword replace parameter as without extension method you will do this Print(fruits) or Print(numbers)

​

  }

​

}