JavaScript for Beginners

JavaScript is the language of the web on the browser side, and also a widely used server-side language (Node.js). It's a good second language, and a mandatory step for anything interactive on a page.

This guide assumes HTML/CSS basics; if not, start with HTML & CSS: the fundamentals.

01 — Where it runs

Browser and server

In the browser, JavaScript reacts to clicks, modifies the page, calls APIs. With Node.js, it runs server-side for tools, APIs, scripts. The language is the same, the environment changes.

02 — The fundamentals

What you need to know first

• Variables (let, const), types, operators.
• Conditionals, loops, functions (including arrow functions).
• Arrays and methods (map, filter, reduce), objects.
• Asynchronous programming: promises and async/await.

03 — The DOM

Acting on the page

Selecting elements, listening for events, modifying content and classes. This is what makes a page come alive. Watch for pitfalls: forgetting to remove a listener, manipulating the DOM before it's ready.

04 — A first project

Small, finished, interactive

A to-do list, a quiz, a converter, a mini-game, or a page that consumes a public API with fetch. Publish it. It's your proof.

05 — What comes next

Choosing a framework later

Once you've got the language down, a framework (React, Vue, Svelte) becomes useful. Picking it up too early hides fundamentals you'll miss later.

06 — Frequently asked questions

Frequently Asked Questions

JavaScript or Python first?

For interactive web, JavaScript. For data, automation and AI, Python. The two complement each other.

Should I learn React right away?

No. The language fundamentals and the DOM first; React next, once its benefits become obvious.

When should I learn TypeScript?

After becoming comfortable with JavaScript. TypeScript adds useful types as projects grow.

07 — Resources & links

Where to go, concretely