一个定时控件，为什么无效？加一个按钮，按钮值是new Date().toLocaleTime

Question

Ba.jsximport React from 'react';const element = (    <div>        <h1>Hello, world!</h1>        <h2>It is {new Date().toLocaleTimeString()}.</h2>    </div>);function tick() {    element}class Clock extends React.Component {    setInterval(tick, 1000);    render() {        return (            element        );    }}export default Clock;