Property ‘map’ Does Not Exist on Type ‘observable‘

You need to import the map operator:

import 'rxjs/add/operator/map'

Or more generally:

import 'rxjs/Rx';

Notice: For versions of RxJS 6.x.x and above, you will have to use pipeable operators as shown in the code snippet below:

import { map } from 'rxjs/operators';
import { HttpClient } from '@angular/common/http';
 
// ...
export class MyComponent {
  constructor(private http: HttpClient) { }
  getItems() {
    this.http.get('https://example.com/api/items').pipe(map(data => {})).subscribe(result => {
      console.log(result);
    });
  }
}

This is caused by the RxJS team removing support for using See the breaking changes in RxJS’ changelog for more info.

From the changelog:

operators: Pipeable operators must now be imported from rxjs like so: import { map, filter, switchMap } from 'rxjs/operators';. No deep imports.