using System;

​

public class Program

{

    public static void Main()

    {

        // write to console the date format using the extension method

        //Console.WriteLine(new DateTime(2014,09,08).ToMyFormat());

        // write to console the date format using the extension method - with bool parameter

        //Console.WriteLine(new DateTime(2014,09,08).ToMyFormat(false));

        // write to console the string format using the string extension method

        //string myString = "this is my string";

        //Console.WriteLine(myString.ToMyFormat());

    }

}

​

​

public static class MyExtensions

{

    // extension method - specified using the 'this' keyword as the first parameter

    public static string ToMyFormat(this DateTime dateTime)

    {

        return "My format " + dateTime.ToString("yyyy-MM-dd");

    }

    public static string ToMyFormat(this DateTime dateTime, bool reverse)

    {

        string result = string.Empty;

        return result = reverse ? "My format " + dateTime.ToString("yyyy-MM-dd") : "My format " + dateTime.ToString("dd-MM-yyyy");

    }

    public static string ToMyFormat(this string mystring)

    {

        return "My format " + mystring.ToUpper();

    }

​

}