//***********************************************************************************************
//1.Nested Types(类型嵌套）
//_______________________________________________________________________________________________
//介绍
//枚举类型常被用于实现特定类或者结构体的功能。我们可以在多种变量环境中方便的定义通用的结构体或者类，Swift 支持枚举，类，结构体为支持嵌套类型
//***********************************************************************************************
//2.Nested Types in Action(类型嵌套实例）
struct BlackjackCard {
// nested Suit enumeration
enum Suit: Character {
case Spades = "♠",Hearts = "♡",Diamonds = "♢",Clubs = "♣"
}
// nested Rank enumeration
enum Rank: Int {
case Two = 2,Three,Four,Five,Six,Seven,Eight,Nine,Ten
case Jack,Queen,King,Ace
struct Values {
let first: Int,second: Int?
}
var values: Values {
switch self {
case .Ace:
return Values(first: 1,second: 11)
case .Jack,.Queen,.King:
return Values(first: 10,second: nil)
default:
return Values(first: self.rawValue,second: nil)
}
}
}
// BlackjackCard properties and methods
let rank: Rank,suit: Suit
var description: String {
var output = "suit is \(suit.rawValue),"
output += " value is \(rank.values.first)"
if let second = rank.values.second {
output += " or \(second)"
}
return output
}
}
let theAceOfSpades = BlackjackCard(rank: .Ace,suit: .Spades)
println("the AceOfSpades: \(theAceOfSpades.description)") //尽管 Rank 和 Suit 嵌套在 BlackjackCard 中,但仍可被引用,所以在初始化实例时能够通过枚举类型中的成员名称(.Ace 和 .Spades)单独引用
//3.Referring to Nested Types(类型嵌套的引用）
//_______________________________________________________________________________________________
//实例代码演示类型嵌套的引用
//在外部对嵌套类型的引用,是以被嵌套类型的名字为前缀,加上所要引用的属性名
let heartsSymbol = BlackjackCard.Suit.Hearts.rawValue
println(heartsSymbol)
