Javascript使用react js获取H:M:S格式的日期

const now = new Date();
const hours = now.getHours();
const minutes = now.getMinutes();
const seconds = now.getSeconds();

import React, { Component } from 'react';

class Clock extends Component {
  constructor(props) {
    super(props);
    this.state = {
      hours: 0,
      minutes: 0,
      seconds: 0
    };
  }

  componentDidMount() {
    this.timer = setInterval(() => {
      const now = new Date();
      const hours = now.getHours();
      const minutes = now.getMinutes();
      const seconds = now.getSeconds();
      this.setState({ hours, minutes, seconds });
    }, 1000);
  }

  componentWillUnmount() {
    clearInterval(this.timer);
  }

  render() {
    const { hours, minutes, seconds } = this.state;
    return (
      <div>
        <h1>{hours}:{minutes}:{seconds}</h1>
      </div>
    );
  }
}

export default Clock;