An acquaintance of mine wanted to add JavaScript to their engineering toolbox but they only learnt OOP with Java so far. I reviewed my JavaScript stash of links, discarded the outdated ones and ordered them:

Resources for learning JavaScript (and its ecosystem) in 2020

• Links are introduced in suggested order of reading
• Intended target: someone knowing to program but not in JavaScript
• all resources are free

Why?

1. Why investing in JavaScript? (blog post coming soon)

Fundamentals

1. A re-introduction to JavaScript (JS tutorial) https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript
2. Dan Abramov's "Just JavaScript" 1 to 9 https://offirmo-backups.github.io/my-time-machine/Dan%20Abramov%20-%20Just%20JavaScript/01.%20Mental%20Models.html
3. Mozilla's JavaScript Guide https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide
4. Promises https://web.dev/promises/
5. Eloquent JavaScript with an intro to the browser and node https://eloquentjavascript.net/
6. fetch intro: https://developers.google.com/web/updates/2015/03/introduction-to-fetch
7. async/await https://developers.google.com/web/fundamentals/primers/async-functions
8. 10 JavaScript concepts you need to know for interviews https://dev.to/arnavaggarwal/10-javascript-concepts-you-need-to-know-for-interviews

Advanced fundamentals

1. The Two Pillars of JavaScript Part 1: How to Escape the 7th Circle of Hell https://medium.com/javascript-scene/the-two-pillars-of-javascript-ee6f3281e7f3
2. The Two Pillars of JavaScript Part 2: Functional Programming, How to Stop Micromanaging Everything https://medium.com/javascript-scene/the-two-pillars-of-javascript-pt-2-functional-programming-a63aa53a41a4
3. Event Loop and the Big Picture (just the 1st one of the series for now) https://blog.insiderattack.net/event-loop-and-the-big-picture-nodejs-event-loop-part-1-1cb67a182810
4. 33 Concepts Every JavaScript Developer Should Know https://github.com/leonardomso/33-js-concepts
5. The Keys to JavaScript Mastery https://medium.com/javascript-scene/10-interview-questions-every-javascript-developer-should-know-6fa6bdf5ad95
6. JavaScript Garden = the most quirky parts of the JavaScript programming language how to avoid common mistakes and subtle bugs, as well as performance issues and bad practices http://bonsaiden.github.io/JavaScript-Garden/

Advanced ecosystem

Choose your path: frontend or backend. If you learn a bit of both, you can claim the legendary "fullstack" title.

Advanced: browser (frontend)

1. Roadmap https://roadmap.sh/frontend
2. Intro https://developer.mozilla.org/en-US/docs/Learn/Front-end_web_developer
3. DOM https://developer.mozilla.org/en-US/docs/Glossary/DOM
4. Web APIs https://developer.mozilla.org/en-US/docs/Web/API
5. Flux architecture https://facebook.github.io/flux/docs/in-depth-overview/
6. The core foundations of a delightful web experience https://developers.google.com/web/fundamentals
7. Security https://developers.google.com/web/fundamentals/security

Advanced: node (backend)

1. Roadmap https://roadmap.sh/backend
2. Setting up a JS environment https://medium.com/javascript-scene/setting-up-a-new-macbook-for-javascript-development-289df3f8f9
3. node basics http://nodejs.org/
4. express https://expressjs.com/
5. NodeJS Event Loop:
   1. Event Loop and the Big Picture https://blog.insiderattack.net/event-loop-and-the-big-picture-nodejs-event-loop-part-1-1cb67a182810
   2. Timers, Immediates and Process.nextTick https://blog.insiderattack.net/timers-immediates-and-process-nexttick-nodejs-event-loop-part-2-2c53fd511bb3
   3. Promises, Next-Ticks, and Immediates https://blog.insiderattack.net/promises-next-ticks-and-immediates-nodejs-event-loop-part-3-9226cbe7a6aa
   4. Handling IO https://blog.insiderattack.net/handling-io-nodejs-event-loop-part-4-418062f917d1
   5. Event Loop Best Practices https://blog.insiderattack.net/event-loop-best-practices-nodejs-event-loop-part-5-e29b2b50bfe2
   6. New Changes to the Timers and Microtasks in Node v11.0.0 https://blog.insiderattack.net/new-changes-to-timers-and-microtasks-from-node-v11-0-0-and-above-68d112743eb3
   7. JavaScript Event Loop vs Node JS Event Loop https://blog.insiderattack.net/javascript-event-loop-vs-node-js-event-loop-aea2b1b85f5c
6. Security TODO

Even more advanced

1. Jest, a delightful JavaScript Testing Framework https://jestjs.io/
2. TypeScript https://www.typescriptlang.org/
3. React:
   1. JavaScript fundamentals before learning React https://www.robinwieruch.de/javascript-fundamentals-react-requirements
   2. Roadmap https://roadmap.sh/react
   3. Official React documentation it's very good https://reactjs.org/
4. Progressive Web Apps https://web.dev/progressive-web-apps/
5. System design primer https://github.com/donnemartin/system-design-primer
6. GraphQL https://graphql.org/

Any other good resource I missed? Please share them in a comment.

Also published as a gist

Credits: https://dev.to/chrisachard/how-to-write-your-first-post-on-dev-c3k for the tips