Modern JavaScript — from foundations to internals.
A structured path through the language. 57 lessons across 7 modules, written for readers who want mechanics, not magic. Free. No signup.
The curriculum
JavaScript Foundations
Variables, types, operators, conditionals, loops — the building blocks every JavaScript developer needs.
Functions Deep Dive
Declarations, parameters, hoisting, scope, closures, `this`, higher-order, pure functions — everything that makes functions the heart of JS.
Objects, Arrays & Iteration
Object literals, array methods, spread and destructuring, iterators, generators, symbols, and weak collections.
Classes & OOP
Prototypes, classes, inheritance, private fields, and when composition beats inheritance.
Asynchronous JavaScript
Callbacks, promises from scratch, async/await, error handling, and the event loop that powers it all.
Modern JS Internals
ES modules, ES2024 features, type coercion gotchas, memory and garbage collection.
Browser & DOM
DOM basics, events and delegation, forms, the Fetch API, and browser storage.
Standard Library Deep Dive
Strings, numbers and BigInt, dates and Intl, and JSON — the built-in types you use every day.
Regular Expressions
Regex syntax from basics through lookarounds, named groups, Unicode property escapes, and real-world patterns.
Advanced JavaScript
Proxy and Reflect, async iteration, the Streams API, and Web Workers — the meta-programming and concurrency primitives.
Beyond-DOM Browser APIs
IndexedDB, the observer APIs (Intersection, Resize, Mutation), Web Components, and Service Workers for PWAs.
Why this tutorial
- Mechanics first. Each lesson explains what’s actually happening, not how to copy-paste a snippet.
- ES2024-current. No legacy noise — modern JS as it actually exists today.
- Stands alone. Every lesson is a complete article you can read standalone or in sequence.
- No filler. Concise lessons, code-first, then real-world gotchas.