React ルーティング

import {
	BrowserRouter as Router,
	Route,
	Link,
	Switch} from "react-router-dom";
import "./App.css";

function App() {
  return (
  <Router>
    <nav>
      <ul>
        <li><Link to="/">Home</Link></li>
        <li><Link to="/products">Products</Link></li>
      </ul>
    </nav>
  <Switch>
  <Route exact path='/products'><Products /></Route>
  <Route exact path='/'><Home /></Route>
  <Route><Page404 /></Route>
  </Switch>
  </Router>
);
}
const Home=()=>(<h2>Home</h2>);
const Products=()=>(<h2>Products</h2>);
const Page404=()=>(<h2>Page404</h2>);
export default App;