Swift按枚举宣布的命令排序一系列枚举

Question

我如何对声明的顺序排序我的枚举数组？

enum EducationOptions: String {
    case gcse = "GCSE"
    case aLevel = "A Level"
    case bachelors = "Bachelors"
    case masters = "Masters"
    case doctorate = "Doctorate"
    case other = "Other"
}

var arrayOfEducationOptions: [EducationOptions] = [.masters, .gcse, .aLevel]

我想按枚举中声明的顺序排序阵列deducationoptions以获取[.gcse，.alevel，.masters]

Answer 1

Vadim似乎有正确的想法，但是如果您想对教育的任意列表进行分类，则可以使用这样的代码：

enum EducationOptions: String, CaseIterable {
    case gcse = "GCSE"
    case aLevel = "A Level"
    case bachelors = "Bachelors"
    case masters = "Masters"
    case doctorate = "Doctorate"
    case other = "Other"
}

let allCases = EducationOptions.allCases

var arrayOfEducationOptions: [EducationOptions] = [.masters, .gcse, .aLevel]
    .sorted {allCases.firstIndex(of: $0)! <  allCases.firstIndex(of: $1)! }

arrayOfEducationOptions.forEach { print($0) }

请注意，该代码是一个天真的实现，并且随着案例数量的增长而扩展很差。 （它至少具有o（n²）时间性能，甚至可能更糟（o（n²•log n））。对于要重写的较大枚举它创建一个结构数组，其中包括来自枚举样本阵列的索引，然后对进行排序。

Answer 2

使其符合caseIterable协议，并使用静态allccases属性：

enum EducationOptions: String, CaseIterable {
    case gcse = "GCSE"
    case aLevel = "A Level"
    case bachelors = "Bachelors"
    case masters = "Masters"
    case doctorate = "Doctorate"
    case other = "Other"
}

let arrayOfEducationOptions = EducationOptions.allCases

Answer 3

在枚举中添加可比的协议？

enum EducationOptions: String {
   case gcse = "GCSE"
   case aLevel = "A Level"
   case bachelors = "Bachelors"
   case masters = "Masters"
   case doctorate = "Doctorate"
   case other = "Other"

   var order: Int {
      switch self {
      case .gcse: return 1
      case .aLevel: return 2
      case .bachelors: return 3
      case .masters: return 4
      case .doctorate: return 5
      case .other: return 6
   }
}

extention EquctionOptions: Comparable { 


   static func < (lhs: EducationOptions, rhs: EducationOptions) -> Bool {
      lhs.order < rhs.order
   }
}

然后，您可以对数组进行排序。

let array = [.masters, .gcse, .aLevel]
let sorted = array.sorted(by: { $0 < $1 })

在具有字符串原始值时，可能有更好的方法来设置数组中的订单值，但不是我的头顶