JavaScript · Async JavaScript

Event loop order

Synchronous code runs first, then promise callbacks, then timers. Logging the order is the fastest way to remember it.

javascriptRunnable example javascript course

Syntax

sync → microtask → task

Example

Try it

setTimeout(() => console.log("timeout"), 0);
Promise.resolve().then(() => console.log("microtask"));
console.log("sync");

Reference pages are the quick answer. The course explains the why, shows the full example and ends with a challenge.