And no the question isn't 'convert a number to a string', it's a small function tasked with doing something along those lines.

I don't get why you feel that's insulting. If I were applying for a job speaking French, was asked to translate a simple sentence, and couldn't...I wouldn't expect to be hired. I don't see this much differently.

> And of all the languages I use for daily work I could not 100% tell you what that function is exactly called.

And see, that would be fine. In this example, if one would say 'oh it's in strconv let me look that up' or 'oh can I look up the string formatting symbols' this would be perfectly acceptable, to me.

Writing things like string(i) or i + "x", not so much.