forkJoin Angular 5的MergeMap问题

import { forkJoin, Observable } from 'rxjs';
import { mergeMap } from 'rxjs/operators';
import { HttpClient } from '@angular/common/http';

// 假设有两个HTTP请求需要同时发起
const request1$ = this.http.get('https://api.example.com/data1');
const request2$ = this.http.get('https://api.example.com/data2');

// 使用forkJoin操作符将两个请求合并为一个Observable
forkJoin([request1$, request2$]).subscribe(([response1, response2]) => {
  // 在这里处理两个请求的响应数据
});

// 使用MergeMap操作符将两个请求合并为一个Observable
const combinedRequest$ = request1$.pipe(
  mergeMap(response1 => request2$.pipe(
    map(response2 => [response1, response2])
  ))
);

combinedRequest$.subscribe(([response1, response2]) => {
  // 在这里处理两个请求的响应数据
});