json - 在 iOS 中，当此变量包含 Null 时，如何将 Any 对象类型的变量转换为 String？

Question

问题是当我想将用户变量转换为字符串时，它显示无法读取数据。可能是因为用户对象包含空值。

响应:

SUCCESS: {
    data =     {
        user =         {
            email = "<null>";
            firstName = "<null>";
        };

        //... 
    };
    message = "";
    messageCode = "API_200";
} 

代码:

if let responseDict = response["data"] as? [String : AnyObject] {

    if let user = responseDict["user"] {
       if let userString = user as? String
       {
          var itIsExtracted = true;
       }
    }
}

Answer 1

我看到的是您的 user 对象被声明为 Any。尝试将其设置为字典。

guard let responseDict = response["data"] as? [String : Any],
    let user = responseDict["user"] as? [String : Any] else {
        // There is no user
        return
}

if let userEmail = user["email"] as? String {
    print(userEmail)
    // Can be a result as "<null>" because of server result
}
if let firstName = user["firstName"] as? String {
    print(firstName)
    // Can be a result as "<null>" because of server result
}

我还可以添加@Vadian 所说的内容。责怪网站所有者发送真正的空值，而不是字符串化的空值。