#vanilla javascript
Fernando Doglio
Nov 8, 2021 ⋅ 9 min read

JavaScript Promises: race, all, allSettled, and then

Fernando Doglio Technical Manager at Globant. Author of books and maker of software things. Find me online at fdoglio.com.

Recent posts:

Using Rust And Leptos To Build Beautiful Declarative User Interfaces

Using Rust and Leptos to build beautiful, declarative UIs

Leptos is an amazing Rust web frontend framework that makes it easier to build scalable, performant apps with beautiful, declarative UIs.

Eze Sunday
Nov 30, 2023 ⋅ 10 min read
5 Best JavaScript Multi-Dimensional Array Libraries

5 best JavaScript multidimensional array libraries

Learn more about the 5 best JavaScript libraries for dealing with multidimensional arrays, such as ndarray, math.js, and NumJs.

Pascal Akunne
Nov 30, 2023 ⋅ 4 min read
Dom Scandinaro Leader Spotlight

Leader Spotlight: Leading by experience with Dom Scandinaro

We spoke with Dom about his approach to balancing innovation with handling tech debt and to learn how he stays current with technology.

Jessica Srinivas
Nov 30, 2023 ⋅ 6 min read
Vite Adoption Guide Overview Examples And Alternatives

Vite adoption guide: Overview, examples, and alternatives

Vite is a versatile, fast, lightweight build tool with an exceptional DX. Let’s explore when and why you should adopt Vite in your projects.

David Omotayo
Nov 29, 2023 ⋅ 16 min read
View all posts

3 Replies to "JavaScript Promises: race, all, allSettled, and then"

  1. Mozilla’s web documentation at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all has an good workaround for the problem of rejection stopping Promise.all(). I have been using it without any issues so far:

    var p1 = new Promise((resolve, reject) => {
    setTimeout(() => resolve(‘p1_delayed_resolution’), 1000);

    var p2 = new Promise((resolve, reject) => {
    reject(new Error(‘p2_immediate_rejection’));

    p1.catch(error => { return error }),
    p2.catch(error => { return error }),
    ]).then(values => {
    console.log(values[0]) // “p1_delayed_resolution”
    console.log(values[1]) // “Error: p2_immediate_rejection”

  2. Nice article, but one thing should be noted. You say:

    “By definition,Promise.all will run all your promises until one of the following conditions are met:”

    It’s not true. Promise.all doesn’t run anything. Promises are ALWAYS fired immediately, always. There are no methods to explicitly control Promise’s execution. Promise.all just listens their execution, but doesn’t do anything else.

Leave a Reply