关于VUE传参数的问题

Question

tab.vue:

    <view v-for="(item, index) in list" :key="index" class="tab-scroll_item" :class="{active:activeIndex === index}" @click="clickTab(item, index)">{{item.name}}</view>

    export default {
        name:"tab",
        props:{
            list: {
                type: Array,
                default(){
                    return[]
                }
            },
            tabIndex: {
                type:Number,
                default: 0
            }
        },
        //监听 data, props 值的变化
        watch: {
            tabIndex(newVal, oldVal){
            // tabIndex(newVal){
                console.log(newVal,oldVal);
                this.activeIndex = newVal;
            }
        },
        methods:{
            clickTab(item, index){
                // console.log(item, index);
                this.activeIndex = index ;
                this.$emit('tab',{
                    data:item,
                    index:index
                    })
            }
        },
        data(){
            return {
                 activeIndex: 0
            };
        }

index.vue:

    <tab :list="tabList" :tabIndex="tabIndex" @tab="tab"></tab>

methods: {
            change(current){
                this.tabIndex = current;
                console.log('当前swiper:  ', current);
            },
            tab(data,index){
                console.log(data,index);
                this.activeIndex = index
            }

打印出来：
全部包裹在里面了， index没有拆分出来

{
    "data": {
        "_id": "66d59bbeb9fb236ac3ff03a5",
        "name": "持仓",
        "user": []
    },
    "index": 2
}