Swift：將變量插入標籤？

Question

我想將可變字符插入UIViewController標籤中：

例如， 「Currency = $」當$是一個變量，可能是$，£，€取決於。

你如何編程？

Answer 1

我認爲最好的辦法是爲每個貨幣字符製作單獨的變量，然後將它們附加到字符串中。然後，您可以將該標籤的文本設置爲該字符串。

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

Answer 2

您可以通過在\()這樣包裝的變量使用字符串插值：

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

這會插入變量到周圍的字符串值。 在這裏尋找更多的信息，關於這個主題：https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html

Answer 3

你會做：

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

你想根據您的條件（或多個）改變你的信變種。

下面是一個例子：

// 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 

這裏是一個參考：strings and characters: Apple

希望這有助於！

Answer 4

這是一個乾淨的方式進入這個：

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 = $"