React-基础总结

 使用1、

// js文件，第一部引入React（大写，不然保错）
import React from 'react'
// 创建数组
const arrList = Array.from({length:60},(_item,index)=>index)
const arr = arrList.map(item => <div key={item}>{`${item}秒是${item%2==0?'偶数':'奇数'}`}</div>)
const ele = <div>{arr}</div>
export default ele

　　

// index中的代码
// 引入
import React from 'react'
import {render} from 'react-dom'
// import ele from './day-01-插值'
// import ele from './day-01-条件渲染'
import ele from './01-列表渲染'
// react元素
// const ele = <div>hello world</div>
// 挂载点
let box = document.querySelector('#app')
console.log(box)
// 挂载
render(ele,box)

　　

// package.json
"scripts": {
    "start": "parcel src/index.html",
    "test": "echo "Error: no test specified" && exit 1"
  },