Task 1: Create User Service

  ng generate service user

    import { Injectable } from '@angular/core';

    @Injectable({
      providedIn: 'root'
    })
    export class UserService {

      constructor() {
      }
    }

Task 2: Create getUsers method in UserService

 getUsers(){
     let users =[ "Naresh", "Siva"];
     return users;
 }

Task 3: Call UserService getUsers method from Component

  users:any;
  constructor(private userService:UserService){
     this.users = this.userService.getUsers();
  }

Questions

• What is Dependency Injection ?
• How Service object is getting injected to component constructors ?