Is extending String class with IsNullOrEmpty confusing?

Question

Everyone knows and love String.IsNullOrEmpty(yourString) method.

I was wondering if it\'s going to confuse developers or make code better if we extend String class t

Answer 1

It doesn't just look like you're calling a method on a null variable. You /are/ calling a method on a null variable, albeit one implemented through a static extension method. I had no idea extension methods (which I was already leery of) supported that. This even allows you to do crazy things like:

public static int PowerLength(this string obj)
{
return obj == null ? 0 : obj.Length;
}

From where I'm standing now, I would classify any use of an extension method on a null reference under considered harmful.