Simple Extension Methods: C# Programming
1. Create a namespace for the extension methods. (i.e. ExtensionMethods)
2. Cteate a class. (i.e. MyExtensions)
3. Now create the extension methods in the class.
Here, we are extending string type to have a new extension method 'WordCount':
using System;
using System.Text;
namespace ExtensionMethods
{
    public static class MyExtensions
    {
        public static int WordCount(this String str)
        {
            return str.Split(new char[] { ' ', '.', '?' }, StringSplitOptions.RemoveEmptyEntries).Length;
        }
    }
}
4. Now, lets use this extension method:
using System;
using ExtensionMethods;
namespace ThreadTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = "You are rocking";
            Console.WriteLine(str.WordCount());            
        }
    }
}
5. That's it. Happy coding.
 
