>>I don't think there should be a performance issue. Given:

>>   public static class MyExtensions
>>    {
>>        public static string AddOn(this string s, string s1)
>>        {
>>            return s + s1;
>>        }
>>    }

then

string str = "Hello".AddOn(" Fred");

is just syntatic sugar for

string str = MyExtensions.AddOn("Hello", " Fred");

i.e. as far as the compiler is concerned they are identical
>
>
>
>Actually, I didn't see how there could be any performance issues either ... the guy who told me this though is usually pretty astute about such things, which is why I wondered about it. Could be that he was wrong. ;-)
>
>~~Bonnie

Bonnie,

There might be a very small performance penalty to pay. But that is nothing compared to what we receive in return