How to return data from a fetch and use the data to another function

Question

I want to use the data I get from a fetch request so I return it as an array. The return value(array) will be use to another function but I get a promise :

Promise {<pending>}
__proto__: Promise
[[PromiseState]]: "fulfilled"
[[PromiseResult]]: Array(10)

Below is the complete code

function getEmailList() {
  fetch(myData.root_url + '/wp-json/wp/v2/email', {
    method: "GET",
    headers: {
      'Content-Type': 'application/json'
    }
  }).then(response => {
    return response.json();
  }).then(emails => {
    emails.map((email) => {
      emailArr.push(email.title.rendered)
    })
    return emailArr;
  }).catch(err => console.log('failed', err))
}

function getData() {
  let emailList = getEmailList();
  console.log(emailList)
}

Does this answer your question? [How do I return the response from an asynchronous call?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — Jared Smith, Oct 13 '20 at 02:02

score 0 · Answer 1 · answered Oct 13 '20 at 02:01

0

Use async await

function async getData() {
  let emailList = await getEmailList();
  console.log(emailList)
}

answered Oct 13 '20 at 02:01

iamhuynq

5,357
1
13
36

This won't work as is. OP's function doesn't return anything to await. Your function will just log undefined. – Jared Smith Oct 13 '20 at 02:02

score 0 · Accepted Answer · edited Oct 13 '20 at 02:30

0

Your calling code can be

function getData() {
  getEmailList().then(emailList => console.log(emailList));  
}

edited Oct 13 '20 at 02:30

Oboo Cheng

4,250
3
24
29

answered Oct 13 '20 at 02:05

Rain.To

504
2
7

Thank you for this.. I'll try to read more about asynchronous call.. Cheers – Monmon Oct 13 '20 at 07:04
You need to return `fetch` in `getEmailList()`. – Ahmed ElMetwally Oct 15 '20 at 14:16

score 0 · Answer 3 · answered Oct 13 '20 at 02:07

You need to return fetch in getEmailList() and use async/await in getData().

function getEmailList() {
  return fetch(myData.root_url + '/wp-json/wp/v2/email', {
    method: "GET",
    headers: {
      'Content-Type': 'application/json'
    }
  }).then(response => {
    return response.json();
  }).then(emails => {
    emails.map((email) => {
      emailArr.push(email.title.rendered)
    })
    return emailArr;
  }).catch(err => console.log('failed', err))
}

async function getData() {
  let emailList = await getEmailList();
  console.log(emailList)
}

How to return data from a fetch and use the data to another function

3 Answers3