As Brad Wilson points out one of the nice features of C# 3.0’s extension methods is that they work on null instances. Indeed, why shouldn’t they? They’re just static methods that are invoked in a slightly different way. But this allows a subtle but very pleasing (to me this morning anyway) bit of syntactic sugar for the very commonly used String.IsNullOrEmpty() method.
So instead of:
if (string.IsNullOrEmpty(myString)) ...
you can have the more-readable:
if (myString.IsNullOrEmpty()) ...
by using:
public static class StringExtensions
{
public static bool IsNullOrEmpty(this string str)
{
return string.IsNullOrEmpty(str);
}
}
It’s a very small thing but I like it.
Duncan Smart's Blog 
JINX! http://blogs.ipona.com/dan/archive/2006/09/21/CSharp_30_Extension_Methods_Are_Great.aspx
I’ve mellowed a little on extension methods since my comment on Dan’s post there, though…
Actually, I’ve mellowed a lot. Extension methods rock.
Hmm, it seems I should wait for 18 months before showing James my ideas…..
I liked the extension example above. I tried to create a similiar one for NotEquals but it’s having some errors(An object reference is required for the non-static field, moth, or property ‘string.Equals(string)’
My code:
public static bool NotEquals(this string s)
{
return !string.Equals(s);
}
Any help would be greatly appreciated.
Chris, I guess you’d need 2 parameters, one to hold the ‘this’ reference (say ‘s1’), and one for the one you’re comparing against, e.g. ‘s2’:
public static bool NotEquals(this string s1, string s2)
{
return !s1.Equals(s2);
}
You’d need to check for nulls also, but you get the idea.