将JSON数据转换为Swift 3中的可用变量

目前，我有一些代码将获取我提供的json数据并对其进行解析，但是我将所有内容都打包在for循环中，我不知道如何将其取出

JSON数据：

[
{
"id": 1,
"displayName": "Jacob Blacksten",
"department": "DF",
"mamager": "San",
"office": "NYC",
"util": 2
}
]

工作代码：

do {
   let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers)

      guard let array = json as? [Any] else {return}

      for user in array {
          guard let userDict = user as? [String: Any] else {return}
          guard let id = userDict["id"] as? Int else { return }
          guard let name = userDict["displayName"] as? String else { return}
          guard let department = userDict["department"] as? String else {return}
          guard let manager = userDict["mamager"] as? String else {return}
          guard let office = userDict["office"] as? String else {return}
          guard let util = userDict["util"] as? Int else {return}

                print(id)
                print(name)
                print(department)
                print(manager)
                print(office)
                print(util)
            }

        } catch{
           print(error)
        }

---

您会注意到所有内容都在for循环中，创建了一个包含所有用户的数组。然而，我只有一个用户，我希望能够拉出say id，并将其用作变量，以便稍后在我的应用程序的标签中打印出来。我希望这是有道理的。我基本上只想操纵这个JSON数据，这样我就可以使用它并在我的应用程序的标签中打印它们

如果要在其他地方使用变量，只需将它们保存到循环范围之外的某个地方即可。我建议创建一个User类，并将json中的值保存到User的实例中

// User.swift
class User {
    // Identifier
    let id: Int

    // Instance variables
    var name: String?
    var department: String?
    var manager: String?
    var office: String?
    var util: Int?

    init(withId id: Int) {
        self.id = id
    }
}

然后，你可以把你的循环变成这样

var user: User?

do {
    let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers)

    guard let array = json as? [Any],
      let userDict = array[0] as? [String: Any],
      let id = userDict["id"] as? Int,
      let name = userDict["displayName"] as? String,
      let department = userDict["department"] as? String,
      let manager = userDict["manager"] as? String,
      let office = userDict["office"] as? String,
      let util = userDict["util"] as? Int else { 
        return
    }

    user = User(withId: id)

    user.name = name
    user.department = department
    user.manager = manager
    user.office = office
    user.util = util

} catch{
    print(error)
}

 // Here, the user variable has all the updated info
 userIdLabel?.text = "\(user?.id)"

---

注意：这一切都是在浏览器中完成的，没有测试

为什么要将带有可变容器的类型分配给不可变常量let json？