IndexOf method returns 0 when it should had return -1 in C# / Java

Question

A friend of mine came to me with this strange behavior which i can\'t explain, any insight view would be appreciated.

Im running VS 2005 (C# 2.0), the following code

Answer 1

More fun php actually does a way better job!

php -r "print strpos('test','');"
PHP Warning:  strpos(): Empty delimiter. in Command line code on line 1