在不知道键的情况下快速引用字典键和值 [英] Swift Reference to a Dictionary Key and Value Without Knowing Key

问题描述

我有一个定义为

var users = [[String:String]]() 

数组中的Dictionary是一个简单的用户名+ yes/no flag [[1stUser:Y]，[2ndUser:N]，[3rdUser:N]]

The Dictionary inside the array is a simple username + yes/no flag [[1stUser: Y], [2ndUser: N], [3rdUser: N]]

在TableView单元格配置中，我定义了

In my TableView cell configuration, I defined

let userRecord = users[indexPath.row] as NSDictionary

，并且需要 分配cell.textlabel.text =用户名(字典的键)

and need to assign cell.textlabel.text = username (the key of the dictionary)

检查标记(是/否)，如果是，则为> cell.accessoryType = UITableViewCellAccessoryType.Checkmark

check flag (Y/N) and if Yes > cell.accessoryType = UITableViewCellAccessoryType.Checkmark

在上面的示例中，我应该仅在1stUser旁边得到一个选中标记.

In the example above, I should get a checkmark next to 1stUser only.

问题是如何在不事先知道字典键('1stUser'，'2nduser'等)的情况下引用字典键并检查值(是/否)?我见过的所有Swift字典示例都假设我们知道用于检索其值的实际键(例如，users ["1stUser"]对我没有帮助，因为我事先不知道1stUser的值为Y).

The question is how to refer to the dictionary keys ('1stUser', '2nduser' etc.) without knowing them in advance and check values (Y/N)? All the Swift dictionary examples I have seen assume we know the actual key to retrieve its value (e.g users["1stUser"] does not help as I do not know in advance that 1stUser has a Y).

推荐答案

您应该始终知道字典键.如果不这样做，那说明您的数据结构不正确-未知数据应始终在字典的值中，而永远在键的值中.

You should always know your dictionary keys. If you don't, you're structuring your data wrong - unknown data should always be in the value of a dictionary, never the key.

考虑使用带有两个键的字典:用户名"和标志".

Consider instead using a dictionary with two keys: "username" and "flag".

示例代码:

var users = [[String:String]]()

users.append(["username" : "Aaron", "flag" : "yes"])
users.append(["username" : "AspiringDeveloper", "flag" : "yes"])

let userRecord = users[1]

let username = userRecord["username"]!
let flag = userRecord["flag"]!

或者，您可以构建基本类并完全避免使用字典:

Alternatively, you could build a basic class and avoid the dictionaries entirely:

class User {
    let username: String
    let flag: Bool

    init(username:String, flag:Bool) {
        self.username = username
        self.flag = flag
    }
}

var users = [User]()

users.append(User(username: "Aaron", flag: true))
users.append(User(username: "AspiringDeveloper", flag: true))

let userRecord = users[1]

let username = userRecord.username
let flag = userRecord.flag

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