Variadic Functions in Swift

What is a variadic function? A Variadic function takes in multiple arguments as a parameter. The swift compiler automatically organizes variadic function objects into an array. The arguments of a variadic function are shown by three periods (…) after the argument’s type. A good everyday example of this would be a print statement where you can print multiple objects.

The “Any…” in the autocomplete of our print statement shows a variadic function allowing us to print multiple objects.

Below is another example on how to use a variadic function inside of a function.

func average(_ numbers: Double...) -> Double {
    var total: Double = 0
    for number in numbers {
        total += number
    return total / Double(numbers.count)
average(1, 2, 3, 4, 5)
// Output: 3

Above we have a function that finds the average of our numbers parameter. The numbers parameter is our variadic function, it will take in as many numbers as we want and then use them in an array to calculate the average.

I hope this clears up how a variadic function work!

Happy coding!


Leave a Reply