import React from 'react';
import ReactDOM from 'react-dom';class Welcome extends React.Component {constructor(props) {super(props)this.state = {list: [{title: "第一节课",content: '时间'}, {title: "第一节课",content: '时间'}, {title: "第三节课",content: '时间'}, ]}}render() {/*  let listArr = [];for (let i = 0; i < this.state.list.length; i++) {let item = ( <li ><h3 > { this.state.list[i].title } </h3> <p > { this.state.list[i].content } </p> < /li >)listArr.push(item)} */let listArr = this.state.list.map((item, index) => {return ( <li key = "index" ><h3 > { index }: { item.title } </h3> <p > { item.content } < /p> < /li >)})console.log(listArr)return ( <div ><h1 >今天课程内容 </h1> <ul ><li > { listArr } <h3 >这是标题 </h3> <p > 内容 < /p> < /li > </ul> < /div > )}
}ReactDOM.render( < Welcome / > , document.querySelector("#root"))

运行结果