variadic function _ golang

package main

import (
    "fmt"
)

func sum(nums ...int) {
    fmt.Println(nums, " ")
    total := 0
    for _, num := range nums {
        total += num
    }
    fmt.Println(total)
}

func main() {

    sum(1, 2)
    sum(1, 2, 3)

    nums := []int{1, 2, 3, 4}
    sum(nums...)
}

[1 2]  
3
[1 2 3]  
6
[1 2 3 4]  
10