:::demo 示例

```html
<template>
    <div>
        <v-checkbox-group v-model="cities3">

            <v-checkbox :label="item.value" v-for="(item,index) in checkedCities3" :key="index">{{item.name}}</v-checkbox>

        </v-checkbox-group>
        <div>
            <br/>
            选中的项的value集合:{{cities3}}
        </div>
    </div>
</template>

<script>
    export default{
        data() {
            return {
                checkedCities3:[
                    {name:'上海',value:1},
                    {name:'北京',value:2},
                    {name:'深圳',value:3},
                ],
                cities3:[2],
            };
        },
    }
</script>
```
:::