forkJoin.example.ts

import { Component, OnInit } from '@angular/core';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Observable';

import 'rxjs/Rx';
import 'rxjs/add/observable/forkJoin';

@Component({
  selector: 'example-fork-join',
  templateUrl: 'fork-join.component.html'
})

export class ForkJoinComponent implements OnInit {
  
  dataA: Array<Object> = [];
  dataB: Array<number> = [];
  dataC: Array<string> = [];

  constructor(public http: Http) {}

  ngOnInit() {
   Observable.forkJoin([
        this.http.get('http://www.server.com/dataA').map(res => res.json()), 
        this.http.get('http://www.server.com/dataB').map(res => res.json()), 
        this.http.get('http://www.server.com/dataC').map(res => res.json())
    ])
    .subscribe(([A,B,C]) => {
      this.dataA = A;
      this.dataB = B;
      this.dataC = C;
    });
  }
}