By using the this keyword you can add to (extend) any class, even sealed classes. So
public static string ToTitleCase(this string value)
{
…
}
allows you to do the following;
string state = “south west australia”;
Console.WriteLine(state.ToTitleCase());
You can extend even interfaces so if you create;
public static IEnumerable WhereEven(this IEnumerable values)
{
…
}
You will find the WhereEven method is available on List, Collection, int[ ] and anything else that implements IEnumerable.
