Understanding and Using JavaScript Promises

In this tutorial we cover what JavaScript promises are and show you how to use them to code asynchronous JavaScript. We will look at a couple of examples to help this sink in.

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[ahmedr.]

Bravo! Before I watched your video I was preconditioned that promise in Js is hard to grasp and understand. I got it after 20 min .. amazing content :)

[mattjak]

Thank you. It's a pleasure to watch such detailed and simplified for understanding materials. Thank you so much for your work.

[RameenFallschirmjager]

This concept ain't so easy. It takes multiple iterations to master. I watch your videos more than once. This one is almost excellent!

[amguruprasath]

Don of javascript == Sir, Steven Hancock.

[ayasswain]

Wonderful tutorial on promises. Where is the code of asyncFunction( ) ? I mean the body of asyncFunction( ). Your voice is clear and the way you explain with example code is too good. The best teacher on javascript award goes to you :-) .

[sameershrestha]

At 23:28, what happens when there is an error in the second .then?
Won't the following .then get executed?
It seems like the control flow moves to .catch whenever an Error is created. Is it so? And .then before .catch doesn't returns a promise, how can it work at all?

[alexanderalancahutay]

I really understand what a PROMISE really is because of you. Simple explanation thank you so much..

[NotPastelDreams]

I nearly gave up on Promises until I watched this video. Thank You so much

[RameenFallschirmjager]

I wish we could dine together! We could talk about how to dominate the world with javascript!

[germanduterte]

Thank you for the deep explanation and simple example of what is promises in JavaScript

[sameershrestha]

Does console.log(def) at 21:33 need to be asynchronous?

[fanuel]

Thanks a lot! This was much easier for me to understand compared to other videos I watched

[suemendez]

Promises kept, thanks for the lesson, have a good day.

[konstantinkkk]

you have created asyncFunction() but why you do NOT show the content of it? I have not understood this lesson from the beginning :(

[zameeebasha]

Excellent explaination Steve, you did not mention that promise.then() / catch() methods return a promise in turn, if I am not wrong.

[nikhilkohli]

Hi Steve, can you please post the contents of asyncfunc() and asyncfunc2() ?

[chrislopezzz]

Beautiful teaching .... well explained!

[PixelTB]

Thank you for explaining it well. But I just have one question, does the .then functions itself returns a promise? Because you chained the .catch function to the .then function.

[mukurajpoot]

Sir i am not able to understand ..a function that returns promise which converts the given array of string into uppercase and returns the result after n seconds, where n is the length of input array.

[sarveshsridhar]

getting an error, async function is not defined....help!