Javascript: How to call multiple promise function parallel using observable?

Question

I have multiple promise functions as:

function test1(){
     const numberPromise = new Promise((resolve) => {
          resolve(1);
     });
     return numberPromise;
}

function test2(){
     const numberPromise = new Promise((resolve) => {
          resolve(2);
     });
     return numberPromise;
}

function test3(){
      const numberPromise = new Promise((resolve) => {
          resolve(3);
      });
      return numberPromise;
}

I want to call it parallel just like Promise.all([test1(),test2(),test3()]) but I don't want to use promise, I want to use Observable.

To get this done I am doing this:

import { Observable } from 'rxjs/Observable';
var data=Observable.of(test1(),test2(),test3());
    data.subscribe((data)=>{
            console.log("data :",data);
})

But I am getting the result like :

But I want to get this like :

data :1
data :2
data :3



  [1]: https://i.sstatic.net/0wamC.png

Promises are executed async doesn't that make them parallel ? — Raimonds
– Raimonds, Commented Jun 10, 2019 at 12:29

RDyego · Accepted Answer · 2019-06-10 12:22:10Z

4

Try to use forkjoin

const example = forkJoin(
  //emit 'Hello' immediately
  of('Hello'),
  //emit 'World' after 1 second
  of('World').pipe(delay(1000)),
  //emit 0 after 1 second
  interval(1000).pipe(take(1)),
  //emit 0...1 in 1 second interval
  interval(1000).pipe(take(2)),
  //promise that resolves to 'Promise Resolved' after 5 seconds
  myPromise('RESULT')
);
//output: ["Hello", "World", 0, 1, "Promise Resolved: RESULT"]
const subscribe = example.subscribe(val => console.log(val));

Example here.

answered Jun 10, 2019 at 12:22

RDyego

2761 gold badge4 silver badges6 bronze badges

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

Collectives™ on Stack Overflow

Javascript: How to call multiple promise function parallel using observable?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related