react タイマー

function App() {
	const [date, setDate] = useState(new Date());
	useEffect(() => {
		const timer = setInterval(() => {
			setDate(new Date());
		}, 1000);
		return () => clearInterval(timer);
	}, [setDate]);

	return (
			<h3>{date.toLocaleTimeString()}</h3>
	);
}
export default App;