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

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.