JavaScript

The language of the web: async code, the DOM, and modern syntax.

3 articles

A counter function inside the finished makeCounter scope, still pointing at the variable count

JavaScriptIntermediate

JavaScript Closures Explained: How Functions Remember

What a closure really is, how a JavaScript function keeps its variables after the outer function returns, and the patterns and bugs closures cause.

Nov 8, 20266 min read

The event loop drawn as a cycle: run one task, run every microtask, then render a frame

JavaScriptAdvanced

The JavaScript Event Loop: Tasks, Microtasks and Rendering

Why does a resolved promise always beat setTimeout(fn, 0)? Learn exactly how the event loop schedules tasks, microtasks and repaints, and how to keep long work from freezing the page.

Oct 29, 20267 min read

Timeline comparing three requests run one after another with the same requests run in parallel

JavaScriptIntermediate

Understanding async/await in JavaScript

A practical guide to promises and async/await: how they work, how to handle errors, and how to run tasks in parallel without slowing your app down.

Oct 21, 20264 min read