Swift中的函数参数类型

Question

In Swift Programming Language Guide, under Function Type section, it says “Because the parameter type and the return type can be a tuple type, function types support functions and methods that take multiple parameters and return multiple values.”

Note the use of word "can be" - does it mean parameter type can be something else as well? Or parameter type has to be tuple only?

Answer 1

you can either call a function with tuples OR with arguments

eg

func sum(a: Int, b: Int) -> Int {
  return a + b
}

you could call this:

let numbers = (40,2)
sum(numbers)

or the old way like

sum(40,2)

Answer 2

A tuple means a set of parameters instead of "single" parameters.

The default way means one value per parameter like this:

func setValue( myValue:Int ) { ... }
setValue( 3 )

On the other hand a tuple can be more than one parameter:

func setValues( myValues:(Int,String) ) { ... }
setValues( (1, "Hello") )

So tuples are possible, but the common way is to use only single values