錯誤時嘗試打印兩個值

Question

在它說 的official swift document「的print(_:separator:terminator:)函數是一個全局函數，打印一個或更值，以適當的輸出。」

var welcomeMessage = "Hello" 
var friendlyWelcom = "Hello!" 

print(friendlyWelcom, separator: ",", terminator: "", welcomeMessage, separator: ",", terminator: "") // Why this is not working 

問題正如代碼中的註釋 - 爲什麼print(friendlyWelcom, welcomeMessage)和print(friendlyWelcom, separator: ",", terminator: ""工作但print(friendlyWelcom, separator: ",", terminator: "", welcomeMessage, separator: ",", terminator: "")生成編譯器錯誤？

Answer 1

您不能隨意添加命名參數。相反，您應該將變量作爲第一個參數分隔，並以逗號分隔。然後，他們得到與加盟之間的隔膜和終止底：

print(friendlyWelcom, welcomeMessage, separator: " - ", terminator: "?") 

輸出

您好！ - 你好？

可以有添加儘可能多的變量，如你所願：

print(friendlyWelcom, welcomeMessage, 123, "somethingElse", "etc", separator: " - ", terminator: "!!!!") 

您好！ - 你好 - 123 - somethingElse - etc !!!!