nicowernli

import { Injectable } from '@angular/core';
import { HttpClient, HttpParams } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Planet } from './planet';

@Injectable()
export class PlanetService {

  constructor(private http: HttpClient) {}

nicowernli

const Rx = require('rxjs');

const long$ = Rx.Observable.interval(1000).take(4);
const short$ = Rx.Observable.interval(500).take(4);

long$
  .switchMap(long => short$.map(short => console.log({ long, short })))
  .subscribe();
  
/** Output

nicowernli

const Rx = require('rxjs');

const long$ = Rx.Observable.interval(1000).take(4);
const short$ = Rx.Observable.interval(500).take(4);

long$
  .flatMap(long => short$.map(short => console.log({ long, short })))
  .subscribe(); 

/** Output

nicowernli

const Rx = require('rxjs');

Rx.Observable.interval(1000)
  .map(intervalValue => intervalValue * 2)
  .subscribe(console.log); // 0, 2, 4, 6, 8, 10, 12, 14, 16, etc