async/await

We’ve covered callbacks and promises. Now we get to the latest async feature that will change how we write asynchronous functions in JS.

This is a feature that truly makes asynchronous code much easier to write. Let’s dive right in.

Introduction

An asynchronous function is created using by writing the async keyword before a function. Here’s what it looks like for a standard function.

async function fn() {...}
const fn = async function() {...}

Here’s what it looks like for an arrow function.

const fn = async () => {...}

Inside an asynchronous function, we can use the await keyword to make the function pause and wait for some operation to complete.

Here, I’ve written a function wait that takes in a number and returns a string after that number of seconds. The function fn calls wait. When wait completes and resolves, fn continues executing.

• Note that these asynchronous functions won’t work very well here in Educative’s code blocks. I recommend you use another JS environment such as https://repl.it/site/languages/javascript.

Example