How to handle browser back button in react js code example

Example 1: if back react

import { useHistory } from 'react-router-dom'


const [ locationKeys, setLocationKeys ] = useState([])
const history = useHistory()

useEffect(() => {
  return history.listen(location => {
    if (history.action === 'PUSH') {
      setLocationKeys([ location.key ])
    }

    if (history.action === 'POP') {
      if (locationKeys[1] === location.key) {
        setLocationKeys(([ _, ...keys ]) => keys)

        // Handle forward event

      } else {
        setLocationKeys((keys) => [ location.key, ...keys ])

        // Handle back event

      }
    }
  })
}, [ locationKeys, ])

Example 2: how to make back button react

const BrowserHistory = require('react-router/lib/BrowserHistory').default;

const App = React.createClass({
    render: () => {
        return (
            <div><button onClick={BrowserHistory.goBack}>Go Back</button></div>
        );
    }
});

React.render((
    <Router history={BrowserHistory}>
        <Route path="/" component={App} />
    </Router>
), document.body);