Browser Support ECMAScript 2017 introduced the JavaScript keywords async and await. The following table defines the first browser version with full support for both:
The async function declaration creates a binding of a new async function to a given name. The await keyword is permitted within the function body, enabling asynchronous, promise-based behavior to be written in a cleaner style and avoiding the need to explicitly configure promise chains.
The async keyword transforms a regular JavaScript function into an asynchronous function, causing it to return a Promise. The await keyword is used inside an async function to pause its execution and wait for a Promise to resolve before continuing.
asynchronous code returns a value, but it wraps the value in a Promise, so that the caller can use it to specify the 'then' function to be called when the asynchronous operation finishes.
In this guide, I’ll walk you through everything you need to know about async/await, from the fundamentals to real-world applications with the hopes that you can start using it in your projects today. As you may already know, JavaScript runs on a single thread, which means it can only execute one piece of code at a time.
Learn how modern JavaScript handles asynchronous code using callbacks, promises, and async/await. See clear examples, common pitfalls, and when to use each.
