extension method : Extension « Class « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Class
3. Extension

using System;

    public static class ExtensionMethods
    {
        public static string Right(this string s, int n)
        {
            if (n < 0 || n > s.Length)
                return s;
            else
                return s.Substring(s.Length - n);
        }
    }

    public class Tester
    {
        public static void Main()
        {
            string hello = "Hello";
            Console.WriteLine("hello.Right(-1) = {0}", hello.Right(-1));
            Console.WriteLine("hello.Right(0) = {0}", hello.Right(0));

        }
    }