Javascript:如何使用 observable 并行调用多个 Promise 函数？

Question

我有多个 promise 函数:

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;
}

我想将其称为并行，就像 Promise.all([test1(),test2(),test3()]) 但我不想使用 Promise，我想使用可观察。

为了完成这个任务，我正在这样做:

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

但我得到的结果如下:

但我想得到这样的:

data :1
data :2
data :3



  [1]: /image/0wamC.png

Answer 1

尝试使用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 .