使用 Struct 和函数时在 swift 3 中出现问题

Question

我正在尝试制作一个收款机计算器应用程序，以帮助我更快地从收银机中数钱。例如：我可以输入我有多少张 20 美元的单张钞票，而不是把所有 20 美元的钞票加起来，应用程序就可以计算出总数。这是我的代码，我使用了 Struct 和函数，但运行代码时出错。谢谢

struct Money {
    oneCent: Double
    fiveCent: Double
    tenCent: Double
    quater: Double
    fiftyCent: Double
    rollCent: Double
    rollFive: Double
    rollTen: Double
    rollQuater: Double
    dollarCoin: Double
    dollar: Double
    fiveDollar: Double
    tenDollar : Double
    twentyDollar: Double
    fiftyDollar: Double
    hundredDollar: Double
    oneCent: Double
}

func moneyCalcualate (value at : Money, copies: Double){

    var total : Double = 0.00
    for i in at{
        switch i {
           case oneCent : total = 0.01 * copies
           case fiveCent : total = 0.05 * copies
            case tenCent : total = 0.10 * copies
            case  quater : total = 0.25 * copies
            case  fiftyCent : total = 0.50 * copies
            case  rollCent: total = 0.01 * copies
            case  rollFive: total = 0.01 * copies
            case  rollTen : total = 0.01 * copies
            case  rollQuater : total = 10.00 * copies
            case  dollarCoin : total = 1.00 * copies
            case  dollar : total = 1.00 * copies
            case  fiveDollar : total = 5.00 * copies
            case  tenDollar : total = 10.00 * copies
            case twentyDollar : total = 20.00 * copies
            case fiftyDollar : total = 50.00 * copies
            case hundredDollar : total = 100.00 * copies

        }
    }
    return total
}


moneyCalcualate(value: quater, copies: 2.0)

Answer 1

这是enum 的典型案例。将您的所有货币类型声明为案例，并为每种货币分配原始值。然后您可以创建一个函数，该函数将返回当前类型的给定副本数的总数。

这是一个例子：

enum Money: Double {
    case oneCent = 0.01
    case fiveCent = 0.05
    case tenCent = 0.1
    case quarter = 0.25

    func total(numberOfCopies: Int) -> Double {
        return self.rawValue * Double(numberOfCopies)
    }
}

你这样称呼它：

let moneyInFiveCents = Money.fiveCent
let fiveCents = moneyInFiveCents.total(numberOfCopies: 5)
print(fiveCents)
// prints 0.25

let moneyInQuarters = Money.quarter
let quarters = moneyInQuarters.total(numberOfCopies: 5)
print(quarters)
// prints 1.25

print(fiveCents + quarters)
// prints 1.5

Answer 2

你可以这样试试..

enum Money {
case oneCent
case fiveCent
case tenCent
case quater
case fiftyCent
case rollCent
case rollFive
case rollTen
case rollQuater
case dollarCoin
case dollar
case fiveDollar
case tenDollar 
case twentyDollar
case fiftyDollar
case hundredDollar



static let all : [Money] = [.oneCent , .fiveCent , .tenCent , .quater, .fiftyCent, .rollCent, .rollFive, .rollTen, .rollQuater, .dollarCoin, .dollar, .fiveDollar, .tenDollar, .twentyDollar, .fiftyDollar, .hundredDollar]
}

func moneyCalcualate (value at : Money, copies: Double) -> Double{


var total : Double = 0.00


switch at {
case .oneCent : total = 0.01 * copies
case .fiveCent : total = 0.05 * copies
case .tenCent : total = 0.10 * copies
case .quater : total = 0.25 * copies
case  .fiftyCent : total = 0.50 * copies
case  .rollCent: total = 0.01 * copies
case  .rollFive: total = 0.01 * copies
case  .rollTen : total = 0.01 * copies
case  .rollQuater : total = 10.00 * copies
case  .dollarCoin : total = 1.00 * copies
case .dollar : total = 1.00 * copies
case  .fiveDollar : total = 5.00 * copies
case  .tenDollar : total = 10.00 * copies
case .twentyDollar : total = 20.00 * copies
case .fiftyDollar : total = 50.00 * copies
case .hundredDollar : total = 100.00 * copies

}

return total
}


moneyCalcualate(value: .quater, copies: 2.0)

希望对你有帮助！