How to asynchronously define javascript object property

Question

Can someone help me define an object property asynchronously? My example below returns `name : undefined and I can't find any strategies on how to do this synchronously...

function returnName () {
    setTimeout(function() { 
    return 'John Wick'
  }, 3000);
}

const person = {
    name: returnName(),
  age: 23
}

console.log(person) // person.name returns `undefined`

Thanks in advance!

The "return value" from a timeout is the ID of that timeout... — evolutionxbox, Jun 20 '17 at 14:08
Why don't you wait 3 seconds and then assign the property to the object? — PeterMader, Jun 20 '17 at 14:10

Alexander Staroselsky · Accepted Answer · 2017-06-20T14:17:11.327

Are you able to use something like a Promise to set/log the name of the person only once the name has resolved from function returnName() whether that's through a setTimeout() or an async DB call? A Promise would give you a simple, effective way to only execute an action once the async method has completed and provides you options for handling successes and errors via .then() and .catch().

function returnName() {
  return new Promise(function(resolve, reject) {
    setTimeout(function() {
        return resolve('John Wick');
    }, 3000);
  });
}

let person = { age: 23 };

returnName().then(function(name) {
  person.name = name;
  console.log(person);
});

Here is a jsfiddle demonstrating the functionality.

Hopefully this helps!

How to asynchronously define javascript object property

1 Answers1