0

I have a dictionary like eg:

let dict = Dictionary<Month, Array<Int32>>()

Obj1.price = "10"
Obj1.value = "abc"
Obj1.title = "January"

Obj2.price = "10"
Obj2.value = "def"
Obj2.title = "April"

Obj3.price = "10"
Obj3.value = "pqr"
Obj3.title = "February"

Obj4.price = "4"
Obj4.value = "mnq"
Obj4.title = "April"

dict = [ Obj1: [3,4], Obj2 : [1,2], Obj3: [8,9], Obj4: [3,3] ]

I have a custom array of month 

let sortTemplate = ["April", "May", "June", "July", "August", "September", "October", "November", "December", "January", "February", "March"]

I want to get the dictionary sorted as [ Obj2 : [1,2], Obj4: [3,3], Obj1: [3,4], Obj3: [8,9] ]

In short I am expecting to sort the dictionary according to custom reference array on property of key. I know we cannot have sorted dictionary but want to sort according to custom sortTemplate and insert into Array of dictionaries

Any hint in this regard will be useful. I know we can sort with values and also keys

4

2 回答 2

1

这是一种可能的解决方案，它使用Dictionarys 内置排序功能，但是title在您的示例中将属性显示为自定义enum而不是String. 然后，“排序模板”由enum.

即，enum MonthSortTemplate你的班级MyClass（后者你没有给我们洗澡，所以我自己做了一个 MWE）为：

enum MonthSortTemplate: Int {
    case April = 1
    case January
    case February
    // ... rest of months follows, in the order you prefer
}

class MyClass {
    var price = ""
    var value = ""
    var title: MonthSortTemplate = .April    
}

// Hashable (just some dummy, don't know how you've set this up)
extension MyClass: Hashable {
    var hashValue: Int {
        return price.hashValue ^ value.hashValue
    }
}

// Equatable (just some dummy, don't know how you've set this up)
func ==(lhs: MyClass, rhs: MyClass) -> Bool {
    return lhs.price == rhs.price && lhs.value == rhs.value
}

创建您的MyClass实例，添加到您的字典中，并将.sort(...)后者的函数用于自定义闭包，为这种特定类型的比较指定。

var Obj1 = MyClass()
var Obj2 = MyClass()
var Obj3 = MyClass()

Obj1.price = "10"
Obj1.value = "abc"
Obj1.title = .January

Obj2.price = "10"
Obj2.value = "def"
Obj2.title = .April

Obj3.price = "10"
Obj3.value = "pqr"
Obj3.title = .February

var dict = Dictionary<MyClass, Array<Int32>>()
dict = [ Obj1: [3,4], Obj2 : [1,2], Obj3: [8,9]]

// your custom sort closure, for Dictionary.sort(...) method
let byMonthTemplate = {
    (elem1:(key: MyClass, val: [Int32]), elem2:(key: MyClass, val: [Int32]))->Bool in
    if elem1.key.title.rawValue < elem2.key.title.rawValue {
        return true
    } else {
        return false
    }
}

let sortedDict = dict.sort(byMonthTemplate)
print("\(dict)")

另一种选择——如果你真的喜欢你的类属性title是类型String——是为对象定义<运算符MyClass：

func <(lhs: MyClass, rhs: MyClass) -> Bool {
    // do comparison stuff with strings lhs.title and rhs.title
    // with regard to your ordering of choice (array sortTemplate)
    return ... 
}

在这种情况下，“凌乱”的东西最终会出现在这个函数中，而实际的排序可以非常优雅地执行

let sortedDict = dict.sort { $0.0 < $1.0 }

就个人而言，我更喜欢这个enum解决方案（但是，这是题外话）。

编辑：

根据您的要求，我将为<您的班级提供一个运算符示例MyClass。这绝不是最佳的，但也许你可以从我的例子中改进它。

// add sortTemplate as a static property of MyClass
class MyClass {
    var price = ""
    var value = ""
    var title = "" 
    static let sortTemplate = ["April", "May", "June", "July", "August", "September", "October", "November", "December", "January", "February", "March"]
}

// define < operator for MyClass objects
func <(lhs: MyClass, rhs: MyClass) -> Bool {
    let indexOfLhs = MyClass.sortTemplate.indexOf({$0 == lhs.title})
    let indexOfRhs = MyClass.sortTemplate.indexOf({$0 == rhs.title})
    return indexOfLhs < indexOfRhs
}

// you can now sort your dictionary according to
let sortedDict = dict.sort { $0.0 < $1.0 }
于 2015-12-17T11:36:12.123 回答
0

希望这种帮助，快速而肮脏的方式

let dict = ["Obj1":[3,4],"Obj2":[1,2],"Obj3":[8,9],"Obj4":[3,3]]

let dict1 =  dict.sort { $0.1[0] < $1.1[0]} //Sort by first object in array
let dict2 =  dict1.sort { $0.1[1] < $1.1[1]} //Sort by second object in array

print(dict2)

输出：[("Obj2", [1, 2]), ("Obj4", [3, 3]), ("Obj1", [3, 4]), ("Obj3", [8, 9])]

于 2015-12-17T11:41:44.123 回答