<div id="app">
        <my-com :newmsg="msg"></my-com>
    </div>
const myCom = {
    template:`
            <div>
                <span>我是子组件</span>
                <div>收到父级数据：{{newmsg}}</div>
            </div>
    `,
    props:[‘newmsg‘]
}
new Vue({
    el:‘#app‘,
    data:{
        msg:‘Hello‘
    },
    components: {
        myCom
    }
})

    props: {
        newmsg: {
            type: Number,
            default: "默认值",
            required: true
        }
    }

    <span>父级数据{{msg}}</span>
    <my-com :name="msg" @tellme="tellme"></my-com>
    <div>~~~{{value}}</div>
const myCom = {
    template:`
        <div>
            <span>子组件</span>
            <div>收到父级数据：{{name}}</div>
            <input v-model="val">
        </div>
    `,
    props:{
        name:{
            type:Array,
            default:‘name‘
        }
    },
    data() {
        return{
            val:‘‘
        }
    },
    watch:{
        val(newVal) {
            console.log(newVal);
            this.$emit(‘tellme‘,newVal)
        }
    }
}
new Vue({
    el:"#app",
    data:{
        msg:[1,2,3],
        value:‘‘
    },
    components:{
        myCom
    },
    methods:{
        tellme(value){
            this.value = value
        }
    }
})