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

Just for the fun of it. It also works like that in python

>>> "test".startswith("")
True
>>> "test".index("")
0

Python throws a ValueError instead of the -1 that is nice.

>>> "test".index('r')
Traceback (most recent call last):
  File "", line 1, in 
ValueError: substring not found