对于单个产品：React TypeError：无法读取未定义的属性‘map’：

如何解决对于单个产品：React TypeError：无法读取未定义的属性‘map’：

这是单个产品数据。

const [single,setSingle]= useState([])

setSingle(res.data) (axios set state)


{
  "id": 135,"device_detail": [
    {
      "type": "high-speed","brief": "dsf","model": "ds","serial": "ds"
    },{
      "type": "low-speed","brief": "dfg","model": "hgj","serial": "dsf"
    }
  ],"device_name": "Handpieces","practice_name": "dsf","unit": "dsf","street": "dsf","status": 1,"created_at": "2021-03-02 14:00:58.295738+00:00"
}

当我使用

{single.device_detail.map((subd,index)=>(
(index ? ',' : '') + subd.type
 ))}   

它说TypeError：无法读取未定义的属性'map'：

但是当我为 device_detail 设置另一个状态然后它的工作方式如下：

const [dd,setdd]= useState([])

setdd(res.data.device_detail) (axios set state)

但是，我这不是一个合适的解决方案。

有什么想法吗？