if I replace this line of code
.then((text) => { throw new Error('Failed!') })
.catch(err => console.log(err))
.then(() => console.log('Does that execute?'));with this
.then((text) => { console.log(text) ) })
.then(() => console.log('Does that execute?'));
in your opinion @ljharb what will be output here ?
The promise is async code as I learned, but in this case the first output will be
Timer completed and second Does this execute
what in the case when a timer duration is 10 minutes ? In that case ,
Does this execute will not be output until the timer is done
But in this basic example from MDN ,
let myFirstPromise = new Promise((resolve, reject) => {
// We call resolve(...) when what we were doing asynchronously was successful, and reject(...) when it failed.
// In this example, we use setTimeout(...) to simulate async code.
// In reality, you will probably be using something like XHR or an HTML5 API.
setTimeout( function() {
resolve("Success!") // Yay! Everything went well!
}, 250)
})
myFirstPromise.then((successMessage) => {
// successMessage is whatever we passed in the resolve(...) function above.
// It doesn't have to be a string, but if it is only a succeed message, it probably will be.
console.log("Yay! " + successMessage)
});
output is
Yay! Success
Success
Two identical examples , output console.log in different order
Why ?
Thank you man
WTF
I’m not sure which two examples you’re referring to
Another question about async code execution
function trackUserHandler() {
navigator.geolocation.getCurrentPosition(
(position) => {
setTimeout(() => {
console.log('Position ', position);
}, 2000);
},
(error) => console.log(error)
);
/**
* This line will run before we print
* current position or throw an error
*/
setTimeout(() => {
console.log('Timer done');
}, 1000);
console.log('Getting position');
}
button.addEventListener('click', trackUserHandler);
if I have this code
in this case, our stack is empty
<anonymous>
right ?
when we click on the button,
Getting position will be executed immediately
and other callbacks tasks will be registered as to do
?
this group is useless or what, noone wants to discuss
@mijatovicmile RELAX. chatting on the internet is async. you might not get a response for 24 hours, and that is ok
you're not paying anyone for their time, so you don't get to make demands on it. relax.
so you're not even asking in the right place
this is the one and only
there's a JS channel on freenode IRC tho.
it's the thing that predates slack/gitter/discord/etc by decades
i'm sure you can google some tutorials
so i'm looking at the style guide, if i had like a ternary statement such as :
node !== undefined ? 0 : node.item
is this not good? because the reader of the code might not understand what the 0 stands for, should I be declaring this as a const variable somewhere, it just seems weird. i'm lookin at 13.4 where it says to assign variables where you need them. i don't exactly need it but i think it'd make it more readable right?
node !== undefined ? 0 : node.item
is this not good? because the reader of the code might not understand what the 0 stands for, should I be declaring this as a const variable somewhere, it just seems weird. i'm lookin at 13.4 where it says to assign variables where you need them. i don't exactly need it but i think it'd make it more readable right?