These are very nice questions that probe JavaScript fundamentals and not ephemeral trivia. I suggest you change #4 and #6 so that they don't require knowledge about the behavior of == vs. ===. (Nobody should use == with JavaScript in 2020.) If you think that makes #4 too easy, perhaps you could add whether Object.keys(obj).map(x => parseInt(x)) === Object.values(obj). And as a bonus puzzler, why isn't Object.keys(obj).map(parseInt) the same as Object.keys(obj).map(x => parseInt(x))?
These are very nice questions that probe JavaScript fundamentals and not ephemeral trivia. I suggest you change #4 and #6 so that they don't require knowledge about the behavior of == vs. ===. (Nobody should use == with JavaScript in 2020.) If you think that makes #4 too easy, perhaps you could add whether
Object.keys(obj).map(x => parseInt(x)) === Object.values(obj). And as a bonus puzzler, why isn'tObject.keys(obj).map(parseInt)the same asObject.keys(obj).map(x => parseInt(x))?Love the bonus question! That's quite the trap.