What this line means in Swift?

Question

I\'m now reading Swift 3 book and found this line there:

func sumOf(numbers: Int...) -> Int {

}

and there are just this description:

<

Answer 1

Example for using function with varidic arguments

func log(args: AnyObject ...) {
  var text = ""
  for arg in args {
    text += " \(arg)"
  }
  print("\(text)")
}

log("Arg1", "Arg2")

log("Arg1", "Arg2", "Arg3")

Answer 2

As per the above explanation the variadic arguments are variable number of argument the function takes variable number of arguments in a numbers array. so if you want to print each element you can do so by

func sumOf(numbers: Int...) -> Int {
    var sum:Int = 0

    for num in numbers {
        sum = sum + num
    }
    return sum
}

and the number of int element passed to this number may very.

Answer 3

It's called variadic arguments, explained here.

A variadic parameter accepts zero or more values of a specified type. You use a variadic parameter to specify that the parameter can be passed a varying number of input values when the function is called. Write variadic parameters by inserting three period characters (...) after the parameter’s type name.