it is just attempt of code golfing: https://en.wikipedia.org/wiki/Code_golf
Should not be done for PROD ))

There is ZERO added value in programming like this in commercial applications. Unless you want the company to depend on you entirely for maintenance of production code. If a company allows this, they will reap what they sow sooner than later.

No idea what you're trying to match with that regex, but it's not a kata issue. Either way, updated this kata's Node version, click reset and try again.

No problem, and I almost forgot, check this to properly format your code in the posts.

Given you're just starting, it's not that bad. See other solutions and try looking for higher order methods on MDN Docs. Even without using higher order methods, try refactoring your code to make it smaller (note that you go through the array twice (and once more for the other array) and it can be done in a single pass). You could also write this as a comment of your solution (remember always to mark it as having spoiler content). Good luck.