listing24.go

// Code listing 24: https://play.golang.org/p/7f0JlVhToDD

// [_Variadic functions_](http://en.wikipedia.org/wiki/Variadic_function)
// can be called with any number of trailing arguments.
// For example, `fmt.Println` is a common variadic
// function.

package main

import "fmt"

// Here's a function that will take an arbitrary number
// of `int`s as arguments.
func sum(nums ...int) {
    fmt.Print(nums, " ")
    total := 0
    for _, num := range nums {
        total += num
    }
    fmt.Println(total)
}

func main() {

    // Variadic functions can be called in the usual way
    // with individual arguments.
    sum(1, 2)
    sum(1, 2, 3)

    // If you already have multiple args in a slice,
    // apply them to a variadic function using
    // `func(slice...)` like this.
    nums := []int{1, 2, 3, 4}
    sum(nums...)
}