app.component.ts

import { HttpErrorResponse } from '@angular/common/http';
import { Component, OnInit } from '@angular/core';
import {User} from './user';
import { UserService } from './user.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit{
  public users : User[];

  constructor(private userService : UserService){} 

  ngOnInit(){
    this.getUsers;
  }

  public getUsers(): void{
    this.userService.getUsers().subscribe(
      (response: User[]) =>{
        this.users = response;
        console.log(this.users);
      },
      (error: HttpErrorResponse) =>{
        alert(error.message);
      }
    );
  }
}