react——类组件 函数组件

import React, { Component } from 'react'

export default class App extends Component {
    constructor(){
        super();
        this.state={
            message:"nihaoa liyinhe"
        }
    }
    render() {
        return (
            <div>
                <h2>APPzujianaaaaaaaaaaaa</h2>
                <span>{this.state.message}</span>
            </div>
        )
    }
}

import React, { Component } from 'react'

export default function App(){
    return (
        <div>i m function component!</div>
        
    )
}