how to use link of react router dom code example

Example 1: link router react

<Link to="/about">About</Link>

Example 2: react router link

import React from "react";
import ReactDOM from "react-dom";
import {
  BrowserRouter as Router,
  Switch,
  useLocation
} from "react-router-dom";

function usePageViews() {
  let location = useLocation();
  React.useEffect(() => {
    ga.send(["pageview", location.pathname]);
  }, [location]);
}

function App() {
  usePageViews();
  return <Switch>...</Switch>;
}

ReactDOM.render(
  <Router>
    <App />
  </Router>,
  node
);