The last video on javascript promises you'll ever need to watch

Рет қаралды 20,842

Жыл бұрын

teaching about javascript promises
developer.mozilla.org/en-US/d...
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Пікірлер: 56

@soniablanche5672 Жыл бұрын

funny thing about await is that it works with any object that has a .then()/.catch() method, it doesn't have to be the built-in Promise class. This is pretty useful if one of your library you are using returns a pseudo-promise object or some sort of polyfill.

@AnkitKumar-tp8hc Жыл бұрын

This video is excatly what title says, only video we need to understand promises. By far the best explanation I have ever seen. I have seen your other videos also like subscriber refractor and I totally love it. Please keep up the good work.

@parthmehta6180 Жыл бұрын

I came across your channel a couple days ago, dude you made everything so simple to understand for me! Love the content bro. GODSPEED!

@vamshikrishnareddy76 Жыл бұрын

I was about request you to make a full video on promises after watching your short video on promises but here it is thank you!!

@thydevdom Жыл бұрын

Once again. A video right on time for the questions I’ve been having.

@mattsmith6828 Жыл бұрын

"Promise.reject" is useful when you want a rejected Promise to propagate further down the chain, instead of being immediately resolved. This effectively allows us to change the behavior of Promise chaining so we can skip over ".then" methods that contains code which depends on the initial rejected Promise.

@mavdotjs Жыл бұрын

note that await works on not just promises, but anything with a `then` function, similar to how the $ syntax works on not just stores, but anything with a `subscribe` function

@WebDevCody Жыл бұрын

That’s cool to know, thanks for that info

@syndg Жыл бұрын

Amazing video dude! Have been following your content for a while. You make everything sound easy and approachable!

@vaayuvaahana5024 Жыл бұрын

Learnt a lot! Thanks a ton. Also, can you pls do a video on refresh tokens? I learnt jwt from your video and realised there aren't many videos which explain what refresh toke ns are, and how to implement them. Pls do a video on refresh toke if time permits. Thanks again.

@Dorobila Жыл бұрын

great video and great easter egg too.

@Glinkis Жыл бұрын

A good thing to mention is that instead of using Promise.all, you can initialize all your promises and await them where you need their resolved values. So if you only need one of the values if a condition depending on another resolved value is true, you only need to await one value.

@planetmall2 Жыл бұрын

Great job!

@wateenafzal2963 Жыл бұрын

Truly the last video needed what extention do you use for suggestions in IDE

@wateenafzal2963 Жыл бұрын

founded it in description 😁😊

@SachalChandio Жыл бұрын

Thanks a lot for your service.

@SachalChandio Жыл бұрын

my gratitude.

@KyselPoints Жыл бұрын

Why does my console always print, "Uncaught Reference error, Promise is not defined" even though I write the exact code you just taught? This promise thing is just eating my mind currently. I wrote promise code in vs code, in chrome (snippet), and even then the output is the same. I can't figure out why!

@rajeeshjohn8365 11 ай бұрын

*DOUBT* : Does promises run a certain set of codes synchronously while allowing other codes to run asynchronously? What I am trying to ask is if a code depends on the result of a time consuming expression, it can be wrapped in promises while those that does not require the result of the expression can run asynchronously?

@theofanisbirmpilis7364 Жыл бұрын

it would be really helpful if you made a video about the call stack

@Paxters_ Жыл бұрын

Would be Great to see tutorial about charts. I want to do coingecko clone but cant figure out how to do charts.

@indrajeetgiri8099 Жыл бұрын

from inside this._wrap method you're returning an function with a value as an argument and storing the returned result inside this._then but from where you're calling that function and passing that value can you please explain...

@martDKNY Жыл бұрын

This implementation save value, but do not have state, right? So we can resolve internal promise(in wrap) over again and return another wrapped 'promise'. new Promise makes an object, so where this (res,rej)=>{res(val)}, I mean executor where it will be store? In closure? It execute immediately, but res(val) always return new Promise? Urphh, complicated!

@liquidwater02 Жыл бұрын

For a second I thought the video title said "The last video on javascript promises, i promise".

@marky9275 Жыл бұрын

Great video and explanation, thanks! A little nitpick, I'm sure it's helpful but the linting errors and red highlighting were pretty distracting to watch

@WebDevCody Жыл бұрын

I’ll turn them off next time

@SeibertSwirl Жыл бұрын

Good job babe!!

@mikopiko Жыл бұрын

Babe!?

@alexander3293 Жыл бұрын

@@mikopiko she is his wife

@SeibertSwirl Жыл бұрын

@@YourExecellency bahaha y’all thought I was his stalker huh 😏 thanks for lookin out for him

@gordonfreimann Жыл бұрын

i might be wrong but i think first c# has introduced async await keywords and the workflow.

@WebDevCody Жыл бұрын

Maybe idk, this isn’t a video on c#

@gordonfreimann Жыл бұрын

@@WebDevCody oh i thought it was a python video.

@WebDevCody Жыл бұрын

@@gordonfreimann ah honest mistake, nah this was a video about go

@vamshikrishnareddy76 Жыл бұрын

Do you have any plans on doing projects with nodejs and SQL, orm ?

@WebDevCody Жыл бұрын

I often make videos using prisma which is an orm for sql

@vamshikrishnareddy76 Жыл бұрын

@@WebDevCody oh really i didn't know that. I will search for those tutorials. Is there any specific playlist ?

@mristau_eu Жыл бұрын

every async function will return a promise, so you can chain .then or .catch after the function call

@WebDevCody Жыл бұрын

I regret not mentioning that. I guess I’ll need one more video 😂

@mristau_eu Жыл бұрын

@@WebDevCody will be the last last video then ;) i actually like the fact you can add a catch to every promise that you await inside async function and in there log the actual error and throw it again with self defined error message to send it directly to the outer catch

@_Rohit_Kumaar Жыл бұрын

Happy Coding ... 👍

@FakeRoba Жыл бұрын

WHAT IS THAT ERROR HIGHLIGHT TEXT PLUGIN NAME?

@WebDevCody Жыл бұрын

Error lens

@FakeRoba Жыл бұрын

@@WebDevCody Ty, and sorry for caps!

@owenwexler7214 10 ай бұрын

"The last video on javascript promises you'll ever need to watch" Do you....... PROMISE? I'll see myself out now.

@kim92se64 11 ай бұрын

24 minutes watched

@WebDevCody 11 ай бұрын

@kim92se64 6 ай бұрын

96@@WebDevCody

@eddies.8314 Жыл бұрын

You promise?

@WebDevCody Жыл бұрын

No promises

@whisky8496 Жыл бұрын

@@WebDevCody Promise rejected!

@WebDevCody Жыл бұрын

@@whisky8496 it’s all settled then

@kantyDarius Жыл бұрын

Great work man, you should consider PromiseAllSettled, is pretty useful.

@WebDevCody Жыл бұрын

I think I've used that maybe once or twice, but yeah I could see it's usecase

@Kay8B Жыл бұрын

Promise.allSettled() is good for use cases where you have several promises and your not dependant on all of them resolving, but you still want the ones that did resolve. Promise.all() will reject if one rejects but allSettled will continue even if one fails. Edit: Could you do a video on your linting or zsh, basically your coding setup.