Man… no. This is my #1 pet peeve in this industry. These are not good questions. These are classic, arrogant “stump the developer” questions with little to no practical application. This is on par with asking a Javascript dev to implement a binary tree or linked list. No one needs to know how to do that in JS. On the off chance that you ever do, you can acquire the knowledge in 10 minutes by Googling. It’s what I call “Stackoverflow knowledge.”

Assess candidates’ expertise in core competencies and use of best practices. Expecting them to implement a perfect map method in real-time is utter nonsense.