Waiting for multiple HTTP requests JS

Question

I am trying to make 3 requests to an API and then populate the array "pics" with the image URLs from each JSON response. Everything works fine but due to the asynchronous nature of JS when I return or print the array of URLs it is empty. How can wait until all 3 image URLs to have been added to the array before returning it? I am aware of js promises and async/await but I haven't had much luck getting those to work. Any help would be greatly appreciated.

function getPics(){

let json = "";
let pics = [];

for(i=0; i<3; i++){

  var fetch = new FetchStream(someUrl);

  fetch.on("data", function(chunk){
      json = JSON.parse(chunk);
      pics[i] = json.primaryImageSmall;
});

}

console.log(pics);

};

getPics();

make your function asynchronous, (prefix it with an async keyword), and await anything you need to wait for. i.e. async function fn() { await fetch(someUrl); await fetch(anotherUrl);} — Anish Sinha
– Anish Sinha, Commented Jan 11, 2022 at 21:04
I'd try with async/await, here's a great guide on this topic javascript.info/async-await — Marelons
– Marelons, Commented Jan 11, 2022 at 21:11

Doğukan Akkaya · Accepted Answer · 2022-01-11 21:11:37Z

2

You can use Promises for that.

// Create each stream (in for loop or whatever)
const a = fetch('https://jsonplaceholder.typicode.com/todos/1');
const b = fetch('https://jsonplaceholder.typicode.com/todos/2');
const c = fetch('https://jsonplaceholder.typicode.com/todos/3');

// Then wait for all of them to resolve
Promise.all([a, b, c]).then((res) => console.log(res))

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

answered Jan 11, 2022 at 21:11

Doğukan Akkaya

5231 gold badge3 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

BGPHiJACK Over a year ago

This would be the ideal solution for queue/task handling of many processes at once.

Collectives™ on Stack Overflow

Waiting for multiple HTTP requests JS

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related