今日代码大赏 | React 基础语法再回顾

import React from 'react';

// 功能性组件
const Message = () => {
  return <h1>Hello, React!</h1>;
};

// 类组件
class Clock extends React.Component {
  constructor(props) {
    super(props);
    this.state = { date: new Date() };
  }

  // 组件生命周期方法
  componentDidMount() {
    this.timerID = setInterval(
      () => this.tick(),
      1000
    );
  }

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

  tick() {
    this.setState({
      date: new Date()
    });
  }

  render() {
    return (
      <p>
        React Clock: {this.state.date.toLocaleTimeString()}
      </p>
    );
  }
}

// 组件渲染
ReactDOM.render(
  <div>
    <Message />
    <Clock />
  </div>,
  document.getElementById('root')
);