react组件

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="../node_modules/react/umd/react.development.js"></script>
    <script src="../node_modules/react-dom/umd/react-dom.development.js"></script>
    <script src="../node_modules/babel-standalone/babel.js"></script>
</head>
<body>
    <div id="app">

    </div>
    <script type="text/babel">
        let arr = [1,2,3,4];
        // 根组件默认拿到全局变量为data的值 在子组件传值直接传值进行调用
       class List3 extends React.Component{//必须是大写的首字母
           render(){
               console.log(this);//符号必须是分号不能是逗号
               return(
                            this.props.data.map((item,index)=>{
                            return (
                                <div key={index}>{item}</div>
                            )
                        }
                    )
               )
           }
       }
       function List(arr) {
           return (
               <ul>
                    {
                        arr.map((item,index)=>{
                            return <li key={index}>{item}</li>
                        })
                    }
               </ul>
           )
       }
       function List2(arr) {
           return (
               <ul>
                    {
                        arr.data.map((item,index)=>{
                            return <li key={index}>{item}</li>
                        })
                    }
               </ul>
           )
       }
       ReactDOM.render(
           <div>
                {List(arr)}
                <List2 data={arr} />
                <List3 data={arr}/>
           </div>,
           document.getElementById('app')
       )
    </script>
</body>
</html>
原文地址:https://www.cnblogs.com/l8l8/p/9454306.html