React Js setInterval Method

<html>

<body>
    <div id="app"></div>
    <script type="text/babel">
        const { useState, useEffect, useRef } = React;

function App() {
            const [message, setMessage] = useState("");

useEffect(() => {
                const interval = setInterval(() => {
                    setMessage(new Date().toLocaleTimeString());
                }, 1000);

return () => clearInterval(interval);
            }, []);

return (
                <div id="app">
                    <h3>React Js setInterval Method</h3>
                    <p>Use of setTimeout in React Js</p>
                    <p>{message}</p>
                </div>
            );
        }

ReactDOM.render(<App />, document.getElementById("app"));
    </script>

h3 {
            color: #333;
            font-size: 24px;
            font-weight: bold;
        }

p {
            color: #777;
            font-size: 18px;
            margin-top: 10px;
        }
    </style>
</body>

</html>