How to get an async function to return a text

Question

Why do async turn a return value in to "[object Promise]"

This is the code that I would like to work....

function foo() {
    let res = bar("HELLO")
    console.log(res)
}

async function bar (text) {
    text = text + await getData();
    return (text)
}

function getData () {
    return new Promise((resolve, reject) => {
        // Do a lot of stuff to find myResult
        resolve(myResult)
    })
}

So my question is this... how come this returns HELLO

function foo() {
    let res = bar("HELLO")
    console.log(res)
}

function bar (text) {
    return (text)
}

and this returns [object Promise]

function foo() {
    let res = bar("HELLO")
    console.log(res)
}

async function bar (text) {
    return (text)
}

How do I get the async function to return the text?

`async` functions always return Promises. You must `await` them or call `.then` on them. — CertainPerformance, Jul 04 '18 at 07:21

score 5 · Answer 1 · answered Jul 04 '18 at 07:23

An async function return value is automatically wrapped in a Promise. For you to unwrap that using the async/await syntax, you again need to await that function.

So in your case:

function foo() {
    let res = bar("HELLO")
    console.log(res)
}

Needs to become:

async function foo() {
    let res = await bar("HELLO")
    console.log(res)
}

or you can deal with it in the promise-chaining way:

function foo() {
    bar("HELLO").then(res => console.log(res))
}

Better answer, handles both `await` and `.then` – Andria Jul 04 '18 at 07:29 — Andria, Jul 04 '18 at 07:29

Joven28 · Accepted Answer · 2018-07-04T07:27:10.507

2

You need to use .then(). Try this.

async function bar (text) {
    return text;
}
var test = bar("hello");

test.then((value) => console.log(value));

edited Jul 04 '18 at 07:27

answered Jul 04 '18 at 07:21

Joven28

769
3
12

Damn it!! I forgot THEN!! hahaha - you are right @Joven28 :) how embarrassing LOL . – torbenrudgaard Jul 04 '18 at 07:24

How to get an async function to return a text

2 Answers2