错误时尝试打印两个值

Question

在它说 的official swift document“的print(_:separator:terminator:)函数是一个全局函数，打印一个或更值，以适当的输出。”

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

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

问题正如代码中的注释 - 为什么print(friendlyWelcom, welcomeMessage)和print(friendlyWelcom, separator: ",", terminator: ""工作但print(friendlyWelcom, separator: ",", terminator: "", welcomeMessage, separator: ",", terminator: "")生成编译器错误？

Answer 1

您不能随意添加命名参数。相反，您应该将变量作为第一个参数分隔，并以逗号分隔。然后，他们得到与加盟之间的隔膜和终止底：

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

输出

您好！ - 你好？

可以有添加尽可能多的变量，如你所愿：

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

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