how to add changes every time you route navigate to page in angular

// Place import at the top<br /> import { Router,NavigationStart} from ‘@angular/router’;</p> <p>//Place the code below inside your class<br /> constructor(private router: Router){}</p> <p>ngOnInit(){<br /> this.router.events.subscribe(event =>{<br /> if (event instanceof NavigationStart){</p> <p> }<br /> })<br /> }