如何使用react-router进行404- Not Found寻呼/路由？

npm install react-router-dom

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

const NotFound = () => {
  return (
    <div>
      <h1>404 - Not Found</h1>
      <p>Sorry, the page you are looking for does not exist.</p>
    </div>
  );
};

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

ReactDOM.render(<App />, document.getElementById('root'));