map不是jsx中的函数 [英] map is not a function in jsx

问题描述

此代码块导致映射错误不是功能

This block of code caused error of map is not a function

 {data && (data.devices || {}).map((obj, i) => 
    <div>{obj.name}</div>
 )}

我只是不明白，我已经做了data &&检查数据是否已定义，否则保留地图.还有data.devices || {}来检查devices属性是否存在.

I just don't get it, I already did data && to check data is defined else keep the map. And also data.devices || {} to check if the devices property is there or not.

我console.log(data.devices)返回的是未定义的，但应该回退到对象了吗?为什么它仍然坏了?

I console.log(data.devices) is return undefined but it should fallback to an object right? why is it still breaking?

推荐答案

对于{}没有本机的.map，因此将data.devices || {}替换为data.devices || []

There is no native .map to {}, so replace data.devices || {} to data.devices || []

{(data && data.devices || []).map((obj, i) => 
    <div>{obj.name}</div>
)}

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