Extension Method In C#

using System;

namespace ExtensionMethod

{

public class Program

{

public static void Main(string[] args)

{

string str="Hello World";

int i=0;

//Normal Method

WithouExtCls witCl=new WithouExtCls();

i= witCl.extCharCount("test abce");

Console.WriteLine(i) ;

//Ext Method use as normal method

Console.WriteLine(ExtensionMethodCls.extCharCount("test"));

//Ext Method for string

i=str.extCharCount();

Console.WriteLine(i);

}

}

public static class ExtensionMethodCls

{

public static int extCharCount(this string strChar)

{

return strChar.Length;

}

}

public class WithouExtCls

{

public int extCharCount(string str)

{

return str.Length;

}

}

}