JavaScript From Zero

JavaScript is the only language that runs in every browser on earth, which is why almost nobody chooses it deliberately and almost everybody ends up writing it. That history shows: the language has three ways to do most things, two of which you should ignore, and tutorials written five years apart teach visibly different languages. This course is sequenced to teach the current one and to name the old parts when you meet them, rather than pretending they do not exist.

The first module is deliberately repetitive. Mosh's hour and Traversy's crash course cover much the same ground at different speeds, and watching both is a better use of an evening than watching either twice. The freeCodeCamp course after them is the long reference version — genuinely optional, and better dipped into than sat through.

The middle of the course is where JavaScript stops being a generic programming tutorial. The DOM module is the point of the language: reading and changing a live page is the thing JavaScript does that other languages do not. Then objects and classes, and then the module that most people skip and then regret.

That module is asynchronous JavaScript, and it gets four teachers on purpose. Callbacks, promises and async/await are one idea explained three ways, and the reason so much JavaScript code is frightening is that people learned the third without ever understanding the first. Roughly eight hours of required video, and close to sixty-five in the pool as a whole — three alternative full courses account for most of that, and none of them are meant to be taken alongside the rest. Keep a browser console open throughout — this is a language you can experiment with in the same window you are learning it in.