如何解决如何从特定键对数组排序?
目前,我有一个声明为:
的数组let VitamineARetinol = "VitamineARetinol"
let VitamineABetacarotene = "VitamineABetacarotene"
let VitamineC = "VitamineC"
let VitamineD = "VitamineD"
let Calories = "Calories"
typealias ListOfAliment = [String: [String: Double]]
let Data: ListOfAliment = [
"Orange": [VitamineARetinol: 0.5,VitamineC: 0.3,VitamineD: 0.98,Calories: 100],"Pomme": [VitamineARetinol: 0.2,VitamineC: 0.2,VitamineD: 0.38,Calories: 120],"Poire": [VitamineARetinol: 0.1,VitamineC: 0.7,VitamineD: 0.58,Calories: 140],"Laitue": [VitamineARetinol: 0.3,VitamineC: 0.1,VitamineD: 0.92,Calories: 105],"Banane": [VitamineARetinol: 0.7,VitamineC: 0.01,VitamineD: 0.63,Calories: 122]
]
var ListOfAlimentClassed = Data
我需要通过卡路里键对其进行排序,同时保留所有数组数据,如下所示:
ListOfAlimentClassed = [
"Orange": [VitamineARetinol: 0.5,Calories: 122],Calories: 140]
]
如何在Swift中有效地做到这一点?请帮忙!
解决方法
let sorted = ListOfAlimentClassed.sorted { (($0.1[Calories] as? Double) ?? 0) < (($1.1[Calories] as? Double) ?? 0) }
,
为您的数据创建一个结构,并为其使用数组
struct Aliment {
let name: String
let vitamineARetinol: Double
let vitaminC: Double
let vitaminD: Double
let calories: Double
}
var array = [
Aliment(name: "Orange",vitamineARetinol: 0.5,vitaminC: 0.3,vitaminD: 0.98,calories: 100),Aliment(name: "Pomme",vitamineARetinol: 0.2,vitaminC: 0.2,vitaminD: 0.38,calories: 120),]
array.sort(by: { $0.calories < $1.calories })
在Swift Programming Language书中阅读有关结构的更多信息