Swift playground - 如何将带逗号的字符串转换为带小数的字符串

Question

我是斯威夫特世界的新手.

如何将带逗号的String转换为带小数的String？

代码工作正常,带点(.)

问题是当我使用逗号(,)...时:var price

问题的起源是Decimal法语键盘使用逗号(,)而不是点(.)

如果它是密钥,不知道如何使用NSNumberFormatter或generateDecimalNumbers.有不止一个选择.

//The answer change if "2,25" or "2.25" is used.

var price      : String = "2,25"
var priceFloat = (price as NSString).floatValue

//I need to have 2.25 as answer.

var costString = String(format:"%.2f", priceFloat)

感谢您的时间和帮助!

Answer 1

更新:Xcode 8.2.1•Swift 3.0.2 您可以使用NumberFormatter()将字符串转换为数字.您只需要指定decimalSeparator如下:

extension String {
    static let numberFormatter = NumberFormatter()
    var doubleValue: Double {
        String.numberFormatter.decimalSeparator = "."
        if let result =  String.numberFormatter.number(from: self) {
            return result.doubleValue
        } else {
            String.numberFormatter.decimalSeparator = ","
            if let result = String.numberFormatter.number(from: self) {
                return result.doubleValue
            }
        }
        return 0
    }
}


"2.25".doubleValue // 2.25
"2,25".doubleValue // 2.25

let price = "2,25"
let costString = String(format:"%.2f", price.doubleValue)   // "2.25"

您还应该使用NumberFormat进行货币格式化,因此创建一个只读计算属性货币,扩展FloatingPoint协议以从String doubleValue属性返回格式化字符串.

extension NumberFormatter {
    convenience init(style: Style) {
        self.init()
        self.numberStyle = style
    }
}
extension Formatter {
    static let currency = NumberFormatter(style: .currency)
}
extension FloatingPoint {
    var currency: String {
        return Formatter.currency.string(for: self) ?? ""
    }
}

let costString = "2,25".doubleValue.currency   // "$2.25"

Formatter.currency.locale = Locale(identifier: "en_US")
"2222.25".doubleValue.currency    // "$2,222.25"
"2222,25".doubleValue.currency    // "$2,222.25"

Formatter.currency.locale = Locale(identifier: "pt_BR")
"2222.25".doubleValue.currency    // "R$2.222,25"
"2222,25".doubleValue.currency    // "R$2.222,25"

Answer 2

您可以使用此Swift 3：

let currentAmount = "2,50"

currentAmount = currentAmount.replacingOccurrences(of: ",", with: ".")

print(currentAmount) // "2.50\n"

Answer 3

var price = "2,25"
price = price.replacingOccurrences(of: ",", with: ".")
var priceFloat = (price as NSString).floatValue