自定义组件v-model

    <div id="app">
        <my-input v-model="num"></my-input>
        <h2>{{num}}</h2>

        
    </div>

    <script>
        let myInput = {
            template:`<p><input ref="input" :value="value" @input="$emit('input', $event.target.value)"></p>`,
            props:['value']
        }
        let app = new Vue({
            el:'#app',
            data:
            {
                num:0
            },
            components:
            {
                myInput
            },

        })
    </script>
</body>```