a标签跳新链接，如果链接为空则不跳转

<el-carousel-item v-for="item in slideList" :key="item.id">
    <a v-if="item.link == ‘‘ " href="javascript:;" ><img :src="item.thumb" alt=""></a>
    <a v-else :href="item.link" target="_blank"><img :src="item.thumb" alt=""></a>
</el-carousel-item>