Kyus of old katas cannot be changed.

I am not a pro, but I'm not sure this kata should be difficulty 6? I have completed several of the other Coding Meetup katas and this one feels like it's in the same difficulty range as the difficulty 7 ones.

I think that opinion is a bit harsh for this example. True, eval() would not be recommended in most cases for security reasons, but consider our actual scope: a measly lvl8 kata designed for beginners. In a higher lvl kata or in an actual programming case I would agree with you.

Ranks can't be changed.

For Javascript, at least, I think this kata should be a lvl 8. Don't get me wrong, I am no pro nor I wanna come off as one, but this felt way too easy for a lvl 7 kata.

I think most of us went along the same route with Set, but yours mixes clarity and simplicity. Good job!

I would suggest to use && instead of &. Though usable, the use of a single & is still discouraged.

https://stackoverflow.com/questions/7310109/whats-the-difference-between-and-in-javascript

Seriously! WTH!!! lol o_o

Yes, you're absolutely right @JurgenBlitz. It's like an idiom, a shortcut. i need to incorporate it! Thanks for your comments!

Good thing I wasn't drinking water at the time, or my screen would be a mess right now.