vue3 v-model

<!doctype html>
<html lang="zh-TW">
<head>
<meta charset="UTF-8" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Vue</title>
</head>

<body>
<div id="app">
    <input type="text" name="value" v-model="c.value" />
    ${$root}
</div>

<script src="https://unpkg.com/vue@next"></script>
<script>
var $vue;
var vue_data={a:{'value':'abc'}, b:{'value':''}, c:{'value':'123'}};

const VM={
    data(){return vue_data;},
    compilerOptions:{delimiters:['${', '}']},
    mounted(){
        console.log('Vue mounted');
    },
    updated(){
        console.log('Vue updated');
    },
    methods:{},
    watch:{},
    computed:{},
}
window.onload=()=>{
    $vue=Vue.createApp(VM).mount('#app');
    $vue.b=$vue.a;
    $vue.c=$vue.a;
}
</script>
</body>
</html>