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Question

我见过没有太大的帮助几个类似的SO问题类型斯威夫特不可改变的表达，

我试图更新availabilityTimes为周一timesArray

var availabilityTimes = [ 
     "Monday": [ "available" : true, 
        "times": [ 
         ["startTime": "9:00 am", "endTime": "1:30 pm" ], 
         ["startTime": "2:30 pm", "endTime": "6:00 pm" ], 
         ["startTime": "7:30 pm", "endTime": "9:00 pm" ] 
        ] 
     ], 
     "Tuesday": [ "available" : true, 
        "times": [ 
         ["startTime": "9:00 am", "endTime": "6:00 pm" ] 
        ] 
        ] 
      ] 




var timesArray = [ 
        ["startTime": "9:00 am", "endTime": "1:30 pm" ], 
        ["startTime": "2:30 pm", "endTime": "6:00 pm" ], 
        ["startTime": "7:30 pm", "endTime": "9:00 pm" ] 
        ] 

这里是我的代码，当我打电话了以下的功能，我在代码行0收到一条错误消息

func updateDailyTimes(day: String, timesArray: [[String:String]]){ 

    guard var updatedTimes = self.availabilityTimes as? [String: AnyObject] else{ 
     return 
    } 

    for (key, var value) in updatedTimes { 

     if key == day{ 
      for (key1, value1) in value as! [String : AnyObject]{ 
       if key1 as String == "times" { 
        value["times"] as [[String : String]] = timesArray // I get an error message in this line 
       } 
      } 

     } 
    } 
} 

Answer 1

根据我的评论我的意思是在开始和结束时间的自定义结构Times和结构DailyTimes具有所需性能和变异函数来更新Times阵列：

struct Times { 
    let start : String 
    let end : String 
} 

struct DailyTimes { 
    let weekday : String 
    var available : Bool 
    var times = [Times]() 

    mutating func update(times : [Times]) { 
     self.times = times 
    } 
} 

现在创建所述availableTimes词典：

var availableTimes = ["Monday" : DailyTimes(weekday: "Monday", available: true, times: [Times(start: "9:00 am", end:"1:30 pm"), 
                         Times(start: "2:30 pm", end:"6:00 pm"), 
                         Times(start: "7:30 pm", end:"9:00 pm")]), 
         "Tuesday" : DailyTimes(weekday: "Tuesday", available: true, times: [Times(start: "9:00 am", end:"6:00 pm")])] 

和timesArray数组：

let timesArray = [Times(start: "9:00 am", end:"1:30 pm"), 
        Times(start: "2:30 pm", end:"6:00 pm"), 
        Times(start: "7:30 pm", end:"9:00 pm")] 

由于Times阵列的Monday已经包含timesArray让我们更新的值Tuesday

availableTimes["Tuesday"]?.update(times:timesArray) 

最后证明这一点

print(availableTimes["Tuesday"]?.times) 

另一项改进可以使用DateComponents代替String小号为时代。

Answer 2

在夫特，一个Dictionary是一个结构，它是一个值类型。考虑像原始类型的值类型，如int。

如果你有这样的：

int a = 0 
int b = a 

然后B获得的价值，它们是不相同的。

所以，当你循环字典时，你的（键，值）对实际上不是字典中的东西，它们只是具有相同的值。迭代它时，不要改变值或引用也很重要。这可能会导致奇怪的错误。

enum AvailabilityTimeMarker { 
    case start 
    case end 
} 
enum DayOfTheWeek: String { 
    case monday = "Monday" 
    case tuesday = "Tuesday" 
    case wednesday = "Wednesday" 
    case thursday = "Thursday" 
    case friday = "Friday" 
    case saturday = "Saturday" 
    case sunday = "Sunday" 
} 

typealias Availability = [DayOfTheWeek : AvailabilityDay] 
typealias AvailabilityDay = [String : Any] 
typealias AvailabilityArray = [AvailabilityTime] 
typealias AvailabilityTime = [AvailabilityTimeMarker : String] 

var availabilityTimes: Availability = [ 
    .monday : [ "available" : true, 
       "times": [ 
        ["startTime": "9:00 am", "endTime": "1:30 pm" ], 
        ["startTime": "2:30 pm", "endTime": "6:00 pm" ], 
        ["startTime": "7:30 pm", "endTime": "9:00 pm" ] 
     ] 
    ], 
    .tuesday : [ "available" : true, 
       "times": [ 
        ["startTime": "9:00 am", "endTime": "6:00 pm" ] 
     ] 
    ] 
] 

var timesArray: AvailabilityArray = [ 
    [.start : "9:00 am", .end : "1:30 pm" ], 
    [.start : "2:30 pm", .end : "6:00 pm" ], 
    [.start : "7:30 pm", .end : "9:00 pm" ] 
] 

func updateDailyTimes(day: DayOfTheWeek, timesArray: AvailabilityArray) { 

    let availabilities = self.availabilityTimes 

    var newtimes = availabilities 

    if var newDayAvailability = availabilities[day] { 
     newDayAvailability["times"] = newtimes 

     newtimes[day] = newDayAvailability 

     self.availabilityTimes = newtimes// Since we're not using reference semantics, we have to change the entire value 
    } 
}