Introduction to JavaScript

Introduction to JavaScript

JavaScript is the language of the browser and is also used on the server (Node.js). It is essential for front-end and full-stack roles.

Where JavaScript runs

  • Browsers: Scripts in HTML, or bundled (e.g. React, Vue).
  • Node.js: Server-side, CLI tools, build scripts.
  • Interviews: Often allowed in coding rounds.

Your first script

In the browser console or a .js file run with Node:

javascript
console.log(\"Hello, world!\");

No compilation step; JavaScript is interpreted (or JIT-compiled in engines).

Versions and syntax

Modern JavaScript (ES6+) has let, const, arrow functions, classes, and modules. We use this in the lessons. Transpilers (e.g. Babel) let you use new syntax in older environments.

What comes next

We cover variables and types, conditionals and loops, functions, arrays and objects, DOM basics, async and promises, and ES6+ features.