MDN: Dynamic Scripting with JavaScript

Start with a correction: the module our link points at no longer exists under that name. MDN restructured its learning area, and "JavaScript First Steps" is now part of a much larger module called Dynamic scripting with JavaScript, living under Learn_web_development/Core/Scripting. The old URL still resolves, but what you land on is bigger and differently organised than the title suggests.

What's there now is the best free scaffolded introduction to JavaScript that exists, written and maintained by Mozilla with the same editorial care as the reference docs. Twenty-three articles, three named challenges, and a "Test your skills" exercise page after nearly every topic.

What it covers

The sequence starts with what JavaScript actually is, then throws you straight into building a Guess the Number game in the second article — a good instinct, since it gives you something working before the theory arrives. From there: troubleshooting and error messages, variables, numbers and operators, strings, string methods, arrays, conditionals, loops, functions, return values, events and event bubbling, object basics, DOM scripting, network requests, JSON, and finally debugging and error handling.

Three challenges punctuate it — a silly story generator, an image gallery, and a house data UI that makes you fetch JSON, filter it, render it and handle a form. That last one is a genuine small project, not a toy.

What it assumes you know

MDN is explicit that this module expects you to have done the HTML and CSS modules first. That's a real prerequisite, not a suggestion — the DOM scripting and events articles assume you can read a document structure. It's also worth knowing that MDN's learning area is maintained by a smaller group than the reference docs, so article quality varies a little more than you'd expect from the brand.

Who it's for

People who want structure and free skill-checks without signing up for anything. The Test your skills pages are the standout feature — short, specific, and they tell you which article to reread. Skip it if you want video or a graded certificate; MDN offers neither. Skip it too if you already program in another language, since the pacing is deliberately slow and the first six articles will feel like wading.

Our take

Excellent material with a navigation problem. MDN has reorganised this learning area more than once, which means old bookmarks, old course listings and old blog recommendations all point at names that have moved. The content is worth the confusion — but budget some time for working out where you actually are in the sequence, because the module is considerably longer than the two-to-four hours a title like "First Steps" implies.