在单独的类 [Swift] 中声明变量的类类型

Question

这里有一个类，球员，它有一个类型的变量，运动，可以是篮球或足球。 我希望能够在球员声明中声明运动类型。 有什么建议吗？

class Soccer : Sport {
    override var players : Int { get { return 11 } }
}
class Basketball : Sport {
    override var players : Int { get { return 5 } }
}
class Sport {
    var teamName: String
    var players: Int { get { return 0 } }
    init(teamName: String) {
        self.teamName = teamName
    }
}
class Player {
    let sport : Sport?
    init? (typeOfSport: Soccer, teamName: String) {
        self.sport = Soccer(teamName: teamName)
    }
    init? (typeOfSport: Basketball, teamName: String) {
        self.sport = Basketball(teamName: teamName)
    }
}
let me = Player(typeOfSport: Soccer(), teamName: "chelsea")
let him = Player(typeOfSport: Basketball(), teamName: "wizards")

Answer 1

您也可以像这样使用枚举：

enum Sport {
    case Soccer (teamName : String)
    var players: Int {
        switch self{
            case .Soccer: return 11
            default: return 0
        }
    }
}
class Player {
    let sport: Sport?
    init? (s : Sport){
        self.sport = s
    }
}
Sport.Soccer (teamName: "Cambuur").players

Answer 2

在这种情况下，我建议你的例子是这个解决方案，我不知道是否是更好的方法，但在我对 OOP 的研究中，我相信这是一种很酷的方式来做你的例子。

protocol Sport {
     func getTotalPlayers() -> Int
}
class Soccer: Sport {
      func getTotalPlayers() -> Int {
          return 11
      }
}
class Basketball: Sport {
     func getTotalPlayers() -> Int {
          return 5
     }
}
class Team {
    private var sport: Sport
    private var name: String
    init(sport:Sport, name:String) {
        self.sport = sport
        self.name = name
    }
    func getTeamName() -> String {
        return name
    }
    func getSport() -> Sport {
          return sport
    }
}
class Chelsea: Team {
    init() {
        super.init(sport: Soccer(), name: "Chelsea")
    }
}
class Wizards: Team {
    init() {
        super.init(sport: Basketball(), name: "Wizards")
    }
}
class Player {
    private var team: Team
    init(team: Team) {
        self.team = team
    }
    func getTeamName() -> String {
        return self.team.getTeamName()
    }  
    func getSport() -> Sport {
        return self.team.getSport()
    }
}
let me = Player(team: Chelsea())
let him = Player(team: Wizards())

Answer 3

我找到了一种方法来做到这一点。如果您在播放器初始化函数 Sport.Type 中声明 typeOfSport，然后像这样需要 Sport 初始化方法......

class Soccer : Sport {
override var players : Int { get { return 11 } }
}
class Basketball : Sport {
    override var players : Int { get { return 5 } }
}
class Sport {
    var teamName: String
    var players: Int { get { return 0 } }
    required init(teamName: String) {
        self.teamName = teamName
    }
}
class Player {
    let sport : Sport?
    init? (typeOfSport: Sport.Type, teamName: String) {
        self.sport = Soccer(teamName: teamName)
    }
    init? (typeOfSport: Basketball, teamName: String) {
        self.sport = Basketball(teamName: teamName)
    }
}
let me = Player(typeOfSport: Soccer.self, teamName: "chelsea")
let him = Player(typeOfSport: Basketball.self, teamName: "wizards")