You most likely tried to modify the input string. I added the const qualifier to the prototype
Raised as issue
Huge coincidence: I've just been through a few katas from that series and your comment helped me figure out this one (not a big math guy)
C# fixed and random tests available.
In mathematical terms "" - include, "()"- not include.
Maybe it would be better to get the default greeting also from the databse and not to hardcode it :-) It would be more flexible, in case our hipotetical database changes...
becouse "$1" is not in expected format -> "$1.00". :-)
You're only changing the variables locally.