Swift：将变量插入标签？

Question

我想将可变字符插入UIViewController标签中：

例如， “Currency = $”当$是一个变量，可能是$，£，€取决于。

你如何编程？

Answer 1

我认为最好的办法是为每个货币字符制作单独的变量，然后将它们附加到字符串中。然后，您可以将该标签的文本设置为该字符串。

let currencyCharacter:String = "$" 
let viewControllerLabelText:String = "Currency = " + currencyCharacter 
myViewControllerLabel.text = viewControllerLabelText 

Answer 2

您可以通过在\()这样包装的变量使用字符串插值：

let currency = "$" 
currencyLabel.text = "Currency = \(currency)" 

这会插入变量到周围的字符串值。 在这里寻找更多的信息，关于这个主题：https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html

Answer 3

你会做：

var letter = "$" 
// You create a new uilabel named label 
label.text = "Currency = " + letter 

你想根据您的条件（或多个）改变你的信变种。

下面是一个例子：

// var currency is a string used to 
// read a paragraph 
If(currency == "dollar") 
     letter = "$" 
Else if (currency == "British pound") 
     letter = "£" 
Else if (currency == "yen") 
     letter = "¥" 
... 

label.text = "Currency = " + letter 

这里是一个参考：strings and characters: Apple

希望这有助于！

Answer 4

这是一个干净的方式进入这个：

func currencySymbol(currency: String) -> String { 
    switch currency { 
     case "dollar": return "$" 
     case "British pound": return "£" 
     case "yen": return "¥" 
     ///add others as needed 
     default: return currency 
    } 
} 

let string = "Currency = \(currencySymbol("dollar"))" //"Currency = $"