read.ts（6133）模块'“ ../../../node_modules/rxjs/observable/combineLatest”'没有导出的成员'combineLatest'.ts（2305）

Question

How to combine Observables by combineLatest. combineLatest is not defined

I am using angular js 7.I want to marge tow query string parameter but when I write the obserable.combinelaste([]) then it will give en error.

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { Observable, of, observable } from 'rxjs'
import { combineLatest } from 'rxjs/observable/combineLatest';
@Component({
  selector: 'app-githubfollowers',
  templateUrl: './githubfollowers.component.html',
  styleUrls: ['./githubfollowers.component.css']
})
export class GithubfollowersComponent implements OnInit {

  constructor(private rout:ActivatedRoute ) { }

  ngOnInit() {
    Observable.combineLatest([  this.rout.paramMap,
  this.rout.queryParamMap

    ]);

    this.rout.paramMap.subscribe(prams=>{

    });
    this.rout.queryParamMap.subscribe(prams=>{

    });
  }

}

Answer 1

You import is wrong. You used the import for RXJS v5.

For RxJS v6+, you should use this import :

import { combineLatest } from 'rxjs';

To solve the following error message :

ngOnInit() { Observable.combineLatest([ this.rout.paramMap, this.rout.queryParamMap ]); Property 'combineLatest' does not exist on type 'typeof Observable

You can use combineLatest like this :

combineLatest(this.rout.paramMap, this.rout.queryParamMap)

And you probably have to spend some time to read how to use it: https://www.learnrxjs.io/operators/combination/combinelatest.html