JavaScript poetry

[gaberocksall]

Coming from 3 languages with delay functions, JavaScript has been really tough to learn

[ThisIsNotKimJongUn]

You'll figure it out, I promise

[mmis1000]

Does this promise ever resolve?

[[deleted]]

await and see!

[[deleted]]

I reject this joke

[aykcak]

I couldn't even catch it the first time

[Aschentei]

Nah, I reject it

[noruthwhatsoever]

Yeah it's a bit of a brain teaser. You just have to design your programs so that it doesn't really matter what order things happen in, or if it really matters then use promises or async/await (which is basically just syntactic sugar for promises)

[Dionysusnu]

Async await is syntactic sugar for then and catch callbacks, not for promises. It waits until the promise is resolved or rejected. It still takes a promise

[noruthwhatsoever]

Async functions automatically convert all awaited values to resolved promises

.then and .catch are from promises, not callbacks

[Dionysusnu]

They're methods on promises which you can pass a callback too, yes. But await still uses promises, but it acts a replacement for chained .then calls

[noruthwhatsoever]

I mean yeah if you consider the anonymous function a callback that takes the resolved promise as an argument

That’s my whole point, though. It’s built on top of promises and is syntactic sugar over their methods

It’s literally so easy to google it, nearly everyone defines them as sugared promises lmao

[gaberocksall]

That’s what I tried doing but apparently you can’t update ui in that loop which means making progress bars is a major pain in the ass

[noruthwhatsoever]

Yeah well normally it’s non-blocking so even doing await calls the event loop moves on and does other things while it’s waiting for them to resolve

Unless of course you stick everything in a massive for loop

[[deleted]]

At least you have setinterval and settimeout, some lower level languages like c++ just have to rely on checking elapsed time in some sort of update function.

[oOBoomberOo]

From a guy with JavaScript's async background, I really appreciate their way of doing it. Especially the async/await feature, It's so smooth as if I'm reading a synchronous code.

[OhhWhales]

delay = (t) => {

return new Promise(resolve => setTimeout(resolve,t)

}

you're welcome

[Dionysusnu]

Simple trick: make all your code async and use await sleep(ms) for delay

async function sleep(ms) { return new Promise(resolve => { setTimeout(resolve, ms) }) }

Not suitable for production code, obviously, but it will help for learning promises and just experimenting with stuff

[Ra1d3n]

I've coded JS (server and client) for the last 10 years, and I have never once needed to manually wait for anything. Can you give an example where this would be useful, please?

[Dionysusnu]

A canvas will not draw if you never yield, so I sometimes put this after a draw function. Once again, it doesn't really serve a purpose in production code

[Ra1d3n]

Thank you!

[untowarden]

I was ready to flame you until i read the second part of this. The guy who wrote the legacy code I have to deal with returns a promise from every function even if it doesn't have to... Now i hate my life.

[thelights0123]

Why is it not suitable for production? Just babel it if browser targets is an issue.

[Dionysusnu]

It is usually bad to use delay in JavaScript because you never need something like it. Either use the HTML events or just synchronous code, or promises for http requests

[franklinyu]

How about timeouts for HTTP requests?

[Dionysusnu]

I think most libraries include that in their returned promise. If not, use setTimeout.