What is wrong in this code?

Question

https://code.sololearn.com/WS7HfFiT1lk4/?ref=app

Answer 1

hi Sina
first you need to fix typo ,
promise ==> should be Promise
then you need to use resolve and reject
Regards

Answer 2

navigator.getBattery().then(function(battery) { document.write(battery.level * 100); } )

see this is a promise too but it dowsn't has result or resolve

Answer 3

Warn here you are USING the promise and in this case it accept only the resolved callback (the function passed to .then)

https://developer.mozilla.org/en-US/docs/Web/API/Navigator/getBattery

Answer 4

That its empty :)

Answer 5

We need your code to take a look and help you🙄

Answer 6

☺☺☺excuse me I forgot

Answer 7

You have forget to use resolve (and if needed reject) and use right syntax for Promise (not promise):

function f0(a){
return new Promise((resolve , reject)=>{
var x = 0;
if(x % 2 == 0){
x = a*5
}
else{
x = a*10
}
resolve(x)
})
}
f0(5).then((result)=>{
console.log(result)
})

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

Answer 8

Sina Have you added resolve(x) at end like in my sample code?

Answer 9

Sina dont worry.. He has contacted me for notify something... Dont take cure, we have removed comments

Answer 10

if I want to write it with resolve and result how it is going to be?

Answer 11

why it doesn't console?

Answer 12

yes you say true

Answer 13

Also we can write this code in another code.
so why do we must learn promis in js?

Answer 14

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises

Answer 15

what?