routing example in angular 8

Example 1: how to create app.routing.module.ts in angular 6

ng generate module app-routing --flat --module=app

Example 2: how to add changes every time you route navigate to page in angular

// Place import at the top
import { Router,NavigationStart} from '@angular/router';

//Place the code below inside your class
constructor(private router: Router){}

ngOnInit(){
   this.router.events.subscribe(event =>{
      if (event instanceof NavigationStart){
   		
      }
   })
}