Ask HN: Best way to learn JavaScript in 2019?

I'm a frontend developer and I know enough JS (with JQuery) to get by to create simple web interactivity. It's time for me to learn the fundamentals, so I can then learn libraries like React.

What's the best way to learn? I've completed some beginner level courses on codecademy and others, but forgot much of what I learned within a month or two. I searched here to find books that are recommended, but it seems that many are outdated (without ES6), for instance: Professional JavaScript for Web Developers, which has great reviews, but no ES6. What I know about JS has been learned through doing it and researching the solution and learning bits at a time-- not a great way to learn.

I'm thinking of trying a course on udemy. Along with finding a book to read on the side. Suggestions?

> What I know about JS has been learned through doing it and researching the solution and learning bits at a time

I don't think there is anything wrong with this approach. Most developers learn this way. And many React developers don't know the fundamentals of JS all that well, because you can go a long way in React just by following conventions. So if React is your goal, just go find some tutorials and start doing it.

>... but it seems that many are outdated (without ES6), for instance: Professional JavaScript for Web Developers, which has great reviews, but no ES6.

Professional JavaScript for Web Developers was the text I used to deep dive on the language in 2012, and it was fantastic. The chapters that dealt with prototype inheritance, scope chains, and execution context provided for a very solid command of the language at the time. Nicholas C. Zakas is an excellent author.

Understanding ECMAScript 6: The Definitive Guide for JavaScript Developers 1st Edition was also written by Zakas, although I have not read it. Unfortunately since it was released in 2016, it likely lacks some of the later revisions to ECMAScript that have been ratified since.

Honorable mention includes Secrets of the JavaScript Ninja, but it's also an old book. Despite its campy name, it provided some of the best visual explanations of advanced JavaScript topics I've ever seen. Granted, I just read a few of the chapters.

I recently had to skill up and take the leap from my pre-ES6 knowledge into the bleeding edge, and the way I did that was to just read MDN (Mozilla Developer Network) pages where necessary, maybe the occasional blog post assuming it seemed of sufficient caliber.

Of course, the hardcore way to deep dive is simply read the latest ECMA spec directly, but I wouldn't recommend that route for where you're at right now unless you're really curious about a particular mechanic.

Based on a cursory search and taking a gander at its index, Eloquent JavaScript, 3rd Edition: A Modern Introduction to Programming (December 4, 2018) looks pretty good.

Some other commenters are saying the "learn as you go" approach is sufficient, and it certainly is initially, but at some point I highly recommend deep diving into how more advanced features of the language work so that you have a solid command of the language.

Either way, best of luck and happy learning!

I think a good way is to pick a framework or library and start building something that you would use for yourself. If you choose react then just start building and as you hit things you don't know how to do, refer back to the course or search the Internet for the solution. Just start building something.

read code and practice