Promise State Definitions
| State | Definition |
|---|---|
| Fulfilled | When a promise is resolved successfully |
| Rejected | When a promise failed. |
| Pending | When a promise is “neither fulfilled nor rejected“. |
| Settled | Not really a state but an umbrella term to describe that a promise is either fulfilled or rejected. |
Hey guys ! Once again I'm back with an indepth video were we discuss ES6 Promises. I know that async/await is the new way people prefer to deal with async code but I think it's always good to know about callback functions, promises, and promise methods.
Also In this video we take a look at Promise.allSettled( ) method which is part of ECMAScript 2020 and can be used in the latest release of Node.js.
In this video we'll have a look at how to convert a request which uses callback functions to request that returns a promise. We'll have a look at how to avoid callback hell by promise chaining.
We'll then have a look at promise methods like: Promise.al(),Promise.race(),Promise.any(),Promise.allSettled(),
For those of you who don't use node.js this is a basic template to follow along.
Code Pen : https://codepen.io/midasxiv/pen/RwwoxvX
Make sure you view the 'console' somewhere in the bottom left.
Video Index:
01:44 - Request Package. ( node.js )03:30 - Request Callback function.06:10 - Promise Constructor / Convert callback to promise. (pure JavaScript )11:20 - Promise Chaining & Promise.then()12:43 - Promise.catch() & Promise.reject()14:23 - Promise.all()17:30 - Promise.race()19:30 - Promise.any()19:30 - Promise.allSettled()22:00 - Outro
If you liked the content checkout my youtube channel.
YouTube video :
Top comments (2)
It's got to be said Promise.all() is massively underutilized in my opinion it can really make your code a lot cleaner. Great article.
There is no any link to access the YouTube video, can anyone ??