Extension methods in c#

1) Extension methods need to be defined at a top level namespace.
2) class name does not matter much
3) parameter has "this" with one argument

see below ...
namespace MyUtilities
{
public static class MyOwnMethods
{
public static int myExtFoo(this String str)
{
return str.Split(new char[] { ' ', '.', '?' }).Length;
}
public static int myExtFoo(this int myint)
{
return myint / 2;
}
}
}
// by arguments "this String str" "this int myint" ... I extended string methods and int methods.

now the caller can call it as below ...

using MyUtilities;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string h = "My name is janaganamana";
int y = h.myExtFoo();
y = y.myExtFoo();
MessageBox.Show (y.ToString());
}
}
}


Notice the overloading too..

more practical use @ http://www.janaganamana.net/onedefault.aspx?bid=1002