The code is for an incremental RPG programming game called Bitburner, which uses a version of JavaScript that has some additional game-specific APIs and restrictions (the game originally ran in a web browser)
This code in particular is a (flawed) solution to the first problem the game throws at you, which is finding a way to hack as much in-game money as possible from in-game servers. (The problem is more complicated than it appears at first glance, and I'll try to elaborate if you ask.)
there's documentation , but it's a good way to learn javascript imo. It gives you an environment to interact with javascript and that's a perfect place to go hands-on and learn programming :)