vue常用命令v-model

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>v-model</title>
    </head>
    <script type="text/javascript" src="js/vue.js" ></script>
    <script>
        window.onload = function(){
            //配置是否允许检查代码,方便调试,生产环境中设置为false
            Vue.config.devtools = true;  //检查代码
            Vue.config.productioinTip = false;  //有强迫症的,可以关掉生产中的提示信息
            var vm = new Vue({
                el: "#div1",
                data:{
                    username: "",
                    age: 18,
                    arr: [1,2,3,4,5],
                    flag: true,
                    obj: {
                        id: 100,name: "张三"
                    },
                    msg: 'hello world!'
                }
            });
        }
    </script>
    
    <body>
        <div id="div1">
            名称:<input type="text" v-model="username">
            <br>名字:`username`
            <br>年龄:`age`
            <br>数组:`arr`
            <br>对象:`obj`
            <br>布尔:`flag`
            <br>提示信息:`msg`
        </div>
    </body>
</html>