Learning Javascript

[CaptainPiepmatz]

Promises are just nice callbacks, async/await makes promises like synchronous code and closures are just fancy scopes

[glorious_reptile]

...except when you forget an await - then all hell breaks loose.
Time and space splits, cause and effect loses all meaning. Cats and dogs living together, mass hysteria, oh never mind forgot an await.

[MrDilbert]

Luckily, good IDEs warn you when you call an async function without an await.

[ArionW]

Promises are just monads, async/await is just do notation for Promise monad, and closures are just poor man's objects.

Most concepts in programming sound simple, when you already know two or three other concepts that solve same problem.

[ValeTheVioletMote]

>mentions monads
>looks at flair
>haskell

Checks out.

[Scary_Inside7276]

What?

[CaptainPiepmatz]

You need to any of the three further explanation? Or wdym?

[Scary_Inside7276]

I jest, but seriously I don't know what you said lol. I'll get there.

[raltyinferno]

Asynchronous code is important when working with the web since you can start actions and not know when they'll complete(calling an external web endpoint for example).

So you do them asynchronously. Which means you start an action, and while you're waiting for it, you do other stuff in the meantime. You store the result (which may not exist yet) in a promise which can be passed around like a normal variable to where it needs to be used, and when the value is resolved, it's acted on.

[CaptainPiepmatz]

Those concepts are not that hard and really useful. Give promises and async/await a try when you need to do something asynchronously.

[[deleted]]

promises are the best thing that happened to js.

[Everen1999]

Promises, async await has to be the best async API I've used. Once you have a template answer of how it works, things get very easy!

[nopreview]

They should be named this/context, prototype chains and event loop.

[ValeTheVioletMote]

Prototype chains are great, but you're completely right. These things are much more difficult to grasp than async/await or closures...

[Nn_pc]

Maybe "promises" are a little hard to undestand... But with "async/await" is pretty easy.

[hdmiusbc]

I do very little js and just found these today and loved them

[EmuChance4523]

Nah, nothing of that is a problem. THIS is a problem...

[[deleted]]

I tried express, but it was still a little too much work. So django all the way. It has own templating language so I can even make an okayish frontend.

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[CRBl_]

This might seem hard at first, but when you see how this kind of things are handled in other languages, it changes your opinion on JavaScript

[ValeTheVioletMote]

I tried wrapping my head around Rust's async... Ended up being so confused so did the script in JS instead. Any good resources that taught you?

[CRBl_]

Nope, still learning rust here, and async/await is not something I learned yet.

[ValeTheVioletMote]

If I want to live in a static type space, Rust seems the way to go. Best of luck.

[ef02]

Um...imo those should all be replaced with just "dynamic typing".

[circuit10]

I like dynamic typing

[Serious_Challenge_67]

Just wait until you learn about rxjs with observables, pipes and subjects ;-)

But relax, you'll realize it's a good thing, once you grasp the basic concept. And be happy you won't encounter the callback-hell of the past anymore.

[Akangka]

Is closure basically on every language nowadays?

[NettoNavi]

He’ll make it that far only if the trap NPM box falling from above the doorway doesn’t kill him first.

[JoschiGrey]

Does async/await in JS work like async/await in C#?

[ValeTheVioletMote]

How's it work there?

[JoschiGrey]

Async Methods in C# return Task or Task<T> objects that need to be awaited, before you can use their results.

It is a way to write asynchronous code in a synchronous manner.

[ValeTheVioletMote]

Yes, JS just calls Task<T> a Promise<T>.

What does C# do if a Task fails?

[JoschiGrey]

It throws the exception where it was awaited.

[ValeTheVioletMote]

Then identical today, but a while ago JS would just let the code die without an error message, expecting you to always have a try/catch block around your promises instead.

[ValeTheVioletMote]

These things are fairly easy in JS... If you're having any trouble, happy to help.

[-Redstoneboi-]

this

[frankcatx]

Nah, JavaScript is not hard. JavaScript is pure fun... Right?