时间戳

首页 > 解决方案 > Object.keys.map 不返回原始键

javascript - Object.keys.map 不返回原始键

问题描述

我正在从我的数据库中获取一个对象：示例：

{availability: null
bio: null
category: ""
createdAt: "2020-10-13T13:47:29.495Z"
email: "oznerol@prova.com"
firstName: "Lorenzo"
id: 37
image: null
job: null
lastName: "Del Rosario"
location: ""
password: "$2b$10$J6m71nc8gBXTvEENMwBjt.azNitCsna3LsxaDIUg.B0ztiTm5xFea"
phone: ""
skills: null
updatedAt: "2020-10-13T13:47:29.495Z"
website: ""}

我正在尝试映射此对象以将所有null值更改为''.

这是我的代码：

const [userData, setUserData] = useState()

useEffect( ()=>{
    
  const fetchData = async () => {
    const a = await getUserData(userId);//this retuns the object
    const cleanUserData = Object.entries(a).map(([key, value]) =>
      value === null || undefined ? value = '' : value
    )
    setUserData(cleanUserData);
  };
  fetchData();
},[])

但通过这种方式我改变了我的价值观，但我失去了我的钥匙，结果是这样一个对象：


{0:37
1:"oznerol@prova.com"
2:"$2b$10$J6m71nc8gBXTvEENMwBjt.azNitCsna3LsxaDIUg.B0ztiTm5xFea"
3:"Lorenzo"
4:"Del Rosario"
5:""
6:""
7:""
8:""
9:""
10:""
11:""
12
...}

标签： javascriptarraysreactjsobject

解决方案

两者都Object.entries返回Object.keys一个数组，所以当你使用map它时，结果将是一个数组。reduce改为使用创建新对象，如下所示：

const cleanUserData = Object.entries(a).reduce((acc, [key, value]) => {
  acc[key] = value == null ? '' : value;
  return acc;
}, {});

注意：您的原始测试value === null || undefined不正确，因为这不是您针对两个可能值进行测试的方式，它应该是value === null || value === undefined. 与 javascript 一样，测试value == null（使用 double-equal ==）也足够undefined == null了。

演示：

const a = {availability: null, bio: null, category: "", createdAt: "2020-10-13T13:47:29.495Z", email: "oznerol@prova.com", firstName: "Lorenzo", id: 37, image: null, job: null, lastName: "Del Rosario", location: "", password: "$2b$10$J6m71nc8gBXTvEENMwBjt.azNitCsna3LsxaDIUg.B0ztiTm5xFea", phone: "", skills: null, updatedAt: "2020-10-13T13:47:29.495Z", website: ""};

const cleanUserData = Object.entries(a).reduce((acc, [key, value]) => {
  acc[key] = value == null ? '' : value;
  return acc;
}, {});

console.log(cleanUserData);

推荐阅读