For string reversal, if given a choice of any language and not allowed to use an API, I'd use python just to screw with you. s = 'somestring' print s[::-1] I've encountered 'language trivia' interview questions too many times. Unless you're explicit about wanting an algorithm (and most programmers would be explicit, or at least admit defeat when someone pointed out the vagueness), I would immediately jump to the shortest correct solution: built-in language features.