import { NgModule }       from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
 
import { HomeComponent }  from './home.component';
import { LoginComponent }   from './login.component';
import { RegisterComponent } from './register.component';
 
 const routes: Routes = [
  { path: '', redirectTo: '/home', pathMatch: 'full' },
  { path: 'home', component: HomeComponent },
  { path: 'login', component: LoginComponent },
  { path: 'heroes',   component: RegisterComponent }
 ];
 
 @NgModule({
  imports: [ RouterModule.forRoot(routes) ],
  exports: [ RouterModule ]
 })
 export class AppRoutingModule {}

 navigate(commands: any[], extras?: NavigationExtras) : Promise<boolean>

 interface NavigationExtras {
  relativeTo : ActivatedRoute
  queryParams : Params
  fragment : string
  preserveQueryParams : boolean
  queryParamsHandling : QueryParamsHandling
  preserveFragment : boolean
  skipLocationChange : boolean
  replaceUrl : boolean
}

this.router.navigate(['login']);

this.router.navigate(['login', 1],{relativeTo: route}); 

this.router.navigate(['login', 1],{ queryParams: { name: 1 } }); 

this.router.navigate(['home'], { preserveQueryParams: true }); 

 this.router.navigate(['home'],{ fragment: 'top' });

this.router.navigate(['/role'], { preserveFragment: true }); 

this.router.navigate(['/home'], { skipLocationChange: true });

this.router.navigate(['/home'], { replaceUrl: true });