how to validate a number using a promise

Question

how do I write a promise to validate a number and it resolve should output "the number that was validated" while it reject should say "we want numbers here" when its is not a valid number.
for example,

45 is an actual number; // resolve

we want numbers here // reject

note: it should also accept a number string and reject NaN

Answer 1

function validateNumber(n) {
const promiseANumber1 = new Promise((resolve,reject) => {
if(isNaN(n)) reject(n);
else resolve(n);
});

promiseANumber1.then(v=>{
console.log(`${v} is an actual number`)
}).catch((err) => {
console.log("We want a number here");
});
}

https://code.sololearn.com/czZdLvNzJI4v/?ref=app

Answer 2

Please, post your try

Answer 3

Calviղ
I gave this a try too, and I am wondering, is it better practice to use then + catch to represent the separate branches of execution? I guess it looks cleaner, than passing both paths to 'then'.

https://code.sololearn.com/cZ6WYofRBR97/?ref=app

Answer 4

Tibor Santa yes, your way is the usual way to handle promise.

Answer 5

Thanks, Calviղ, and Tibor Santa
You guys are amazing

Here's my solution

version 1 :
https://code.sololearn.com/cppIO81FC1ve

version 2:
https://code.sololearn.com/cQ2PjH0UeERB

version 3:
https://code.sololearn.com/cypKCvDlc1lk