lovecoding
/
W250511


			
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							<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./babel.min.js"></script>
    <script src="./react.development.js"></script>
    <script src="./react-dom.development.js"></script>
</head>

<body>
    <div id="root"></div>
    <script type="text/babel">
        let root = ReactDOM.createRoot(document.getElementById("root"));
        function App() {
            return (
                <Count />
            )
        }
        // if/else/else-if   switch-case  三元判断
        /**
         * 登录逻辑
         * 用户 => 首页 
         * 非用户 => 登录页
         * 
         * 本地存储
        */
        class Count extends React.Component {
            constructor() {
                super();
                this.state = {
                    token: JSON.parse(localStorage.getItem("token")),
                    msg: {
                        user: '图图',
                        age: 3
                    }
                }
            }
            render() {
                let { token, msg } = this.state;
                return token ?
                    <div>我叫{msg.user},今年{msg.age}</div>
                    :
                    <div>
                        <h1>请登录</h1>
                    </div>


            }
        }

        // if (token) {
        //     return <div>我叫{msg.user},今年{msg.age}</div>
        // } else {
        //     return (
        //         <div>
        //             <h1>请登录</h1>
        //         </div>
        //     )

        // }
        root.render(<App />);
    </script>
</body>

</html>