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Swift:比较扑克牌-二进制比较不能应用

comparison-operators swift

0

zardon · 技术社区 · 6 年前

我在雨燕游乐场有以下代码 Card 结构已创建。

我需要比较卡片,看看哪个值更高。

理想情况下,我还需要检查所有形式的二进制操作 <, >, <=, >=, etc

但是,我不断收到一个错误,上面写着:

error: binary operator '>' cannot be applied to two 'Card' operands if (ace > king) {
    ~~~ ^ ~~~~

另一条消息指出:

注意:“>”的重载存在这些部分匹配的参数列表:((),()),(UInt8,UInt8),(Int8,Int8),(UInt16,UInt16), (Int64,Int64),(UInt,UInt),(Int,Int),(UIContentSizeCategory, UIContentSizeCategory),(日期,日期),(IndexPath,IndexPath), (IndexSet.Index, IndexSet.Index),((A,B),(A,B)),((A,B,C),(A,B, C) ),((A,B,C,D),(A,B,C,D)),((A,B,C,D,E),(A,B,C,D,E)), (ace>国王){

struct Card : Equatable {

    // nested Suit enumeration
    enum Suit: Character {
        case spades = "â ", hearts = "â¡", diamonds = "â¢", clubs = "â£"
    }

    // 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: 11, second: nil)
            case .jack, .queen, .king:
                return Values(first: 10, second: nil)
            default:
                return Values(first: self.rawValue, second: nil)
            }
        }
    }

    // Card 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
    }
}


extension Card {
    public static func == (lhs: Card, rhs: Card) -> Bool {
        return ((lhs.rank == rhs.rank) && (lhs.suit == rhs.suit))
    }
}

// Try to compare two cards
let ace = Card(rank: .ace, suit: .clubs)
let king = Card(rank: .king, suit: .diamonds)

if (ace > king) {
    print ("Ace is higher value")
}
else {
    print ("Ace is NOT higher")
}

我想知道我做错了什么。

1 回复 | 直到 6 年前

1

Dávid Pásztor 6 年前

你需要遵守法律 Comparable < 和 >

extension Card: Comparable {
    static func < (lhs: Card, rhs: Card) -> Bool {
        return lhs.rank.values.first < rhs.rank.values.first
    }
}