如何在默认情况下选择特定页面？

import { Switch, Route } from 'react-router-dom';

function App() {
  return (
    <Switch>
      <Route exact path="/" component={Home} />
      <Route path="/about" component={About} />
      <Route path="/contact" component={Contact} />
      <Route component={NotFound} />
    </Switch>
  );
}

import Vue from 'vue';
import VueRouter from 'vue-router';

Vue.use(VueRouter);

const routes = [
  { path: '/home', component: Home },
  { path: '/about', component: About },
  { path: '/contact', component: Contact },
  { path: '*', component: NotFound }, // 默认路由
];

const router = new VueRouter({
  routes,
});

new Vue({
  router,
  render: (h) => h(App),
}).$mount('#app');

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

const routes: Routes = [
  { path: 'home', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  { path: 'contact', component: ContactComponent },
  { path: '**', component: NotFoundComponent }, // 默认路由
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule],
})
export class AppRoutingModule {}