vue使用elementUI复选框提交的时候变数字

<el-checkbox-group v-model="checkedCities" >
    <el-checkbox  v-for="i in cities" :label="i.id" :key="i.id" >{{i.name}}</el-checkbox>
</el-checkbox-group>
 /
data () {      
   return {        
      checkedCities: [],
      cities:[
        {id:'fushanqu',name:'福山区'},
        {id:'zhifuqu',name:'芝罘区'},
        {id:'laishanqu',name:'莱山区'}
      ],
   };