JavaScript Promise.all()

Definition and usage

Promise.all() Methods return a single Promise from a group of Promises, when all Promises have succeeded.

Instance

// Create a Promise
const myPromise1 = new Promise((resolve, reject) => {
  setTimeout(resolve, 200, "King");
});
// Create another Promise
const myPromise2 = new Promise((resolve, reject) => {
  setTimeout(resolve, 100, "Queen");
});
// Which one is faster, two promises both succeed?
Promise.all([myPromise1, myPromise2]).then((x) => {
  myDisplay(x);
});

Try it yourself

Syntax

Promise.all(iterable)

Parameter

Return value

Browser support

Promise.all() It is a feature of ECMAScript 6 (ES6).

Since June 2017, ES6 (JavaScript 2015) has been supported in all modern browsers:

Promise.all() Not supported by Internet Explorer.