import React from "react";
import {
BrowserRouter as Router,
Switch,
Route,
Link,
useRouteMatch,
useParams
} from "react-router-dom";
export default function App() {
return (
<Router>
<div>
<ul>
<li>
<Link to="/">Home</Link>
</li>
<li>
<Link to="/about">About</Link>
</li>
<li>
<Link to="/topics">Topics</Link>
</li>
</ul>
<Switch>
<Route path="/about">
<About />
</Route>
<Route path="/topics">
<Topics />
</Route>
<Route path="/">
<Home />
</Route>
</Switch>
</div>
</Router>
);
}
function Home() {
return <h2>Home</h2>;
}
function About() {
return <h2>About</h2>;
}
function Topics() {
let match = useRouteMatch();
return (
<div>
<h2>Topics</h2>
<ul>
<li>
<Link to={`${match.url}/components`}>Components</Link>
</li>
<li>
<Link to={`${match.url}/props-v-state`}>
Props v. State
</Link>
</li>
</ul>
{/* The Topics page has its own <Switch> with more routes
that build on the /topics URL path. You can think of the
2nd <Route> here as an "index" page for all topics, or
the page that is shown when no topic is selected */}
<Switch>
<Route path={`${match.path}/:topicId`}>
<Topic />
</Route>
<Route path={match.path}>
<h3>Please select a topic.</h3>
</Route>
</Switch>
</div>
);
}
function Topic() {
let { topicId } = useParams();
return <h3>Requested topic ID: {topicId}</h3>;
}