Relawan kami belum menerjemahkan artikel ini ke dalam Bahasa Indonesia . Bergabunglah dan bantu kami menyelesaikan pekerjaan ini!
The Promise.all(iterable)
method returns a promise that resolves when all of the promises in the iterable argument have resolved, or rejects with the reason of the first passed promise that rejects.
Syntax
Promise.all(iterable);
Parameters
Return value
A Promise
that resolves when all of the promises in the given iterable have resolved, or rejects if any of the promises rejects.
Description
Promise.all passes an array of values from all the promises in the iterable object that it was passed. The array of values maintains the order of the original iterable object, not the order that the promises were resolved in. If something passed in the iterable array is not a promise, it's converted to one by Promise.resolve
.
If any of the passed in promises rejects, the all
Promise immediately rejects with the value of the promise that rejected, discarding all the other promises whether or not they have resolved. If an empty array is passed, then this method resolves immediately.
Examples
Using Promise.all
Promise.all
waits for all fulfillments (or the first rejection).
var p1 = Promise.resolve(3); var p2 = 1337; var p3 = new Promise((resolve, reject) => { setTimeout(resolve, 100, "foo"); }); Promise.all([p1, p2, p3]).then(values => { console.log(values); // [3, 1337, "foo"] });
Promise.all
fail-fast behaviour
Promise.all
is rejected if one of the elements is rejected and Promise.all
fails fast: If you have four promises which resolve after a timeout, and one rejects immediately, then Promise.all
rejects immediately.
var p1 = new Promise((resolve, reject) => { setTimeout(resolve, 1000, "one"); }); var p2 = new Promise((resolve, reject) => { setTimeout(resolve, 2000, "two"); }); var p3 = new Promise((resolve, reject) => { setTimeout(resolve, 3000, "three"); }); var p4 = new Promise((resolve, reject) => { setTimeout(resolve, 4000, "four"); }); var p5 = new Promise((resolve, reject) => { reject("reject"); }); Promise.all([p1, p2, p3, p4, p5]).then(values => { console.log(values); }, reason => { console.log(reason) }); //From console: //"reject" // Evenly, it's possible to use .catch Promise.all([p1, p2, p3, p4, p5]).then(values => { console.log(values); }).catch(reason => { console.log(reason) }); //From console: //"reject"
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Promise.all' in that specification. |
Standard | Initial definition in an ECMA standard. |
ECMAScript 2017 Draft (ECMA-262) The definition of 'Promise.all' in that specification. |
Draft |
Browser compatibility
To contribute to this compatibility data, please write a pull request against this file: https://github.com/mdn/browser-compat-data/blob/master/javascript/promise.json.
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Servo |
---|---|---|---|---|---|---|---|
Basic Support | 32.0 | (Yes) | 29.0 | No support | 19 | 7.1 | No support |
Feature | Android | Chrome for Android | Edge Mobile | Firefox for Android | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic Support | 4.4.4 | 32.0 | (Yes) | 29 | No support | (Yes) | 8.0 |