hm. Maybe it's just because I don't personally excel at this sort of question, but I don't like "trick" questions like this where the interviewer is not forthright with what they're looking for- another way to describe this is "playing mind games" with someone, which is typically considered impolite/antisocial.

I much prefer "Here's a domain problem, how would you solve it" to a vague question where the interviewer has a specific, hard to determine answer in mind. The former directly tests my ability to solve relevant problems, the latter just tests my ability to guess what the interviewer is thinking. In this case I'm perfectly aware of how variable & function declarations are hoisted in JS, but it wasn't clear to me that this was the answer sought- I know the answer but I don't know that's the answer being angled for so I fail at the question. Should this reflect badly on me? I am not sure- this sort of guessing skill may be what this interviewer is looking for. (?)