package main import "fmt" func main() { array := [3]float64{7.0, 8.5, 9.1} x := Sum(&array) // Note the explicit address-of operator to pass a pointer to the array fmt.Printf("The sum of the array is: %f", x) } func Sum(a *[3]float64) (sum float64) { for _, v := range a { // can also with dereferencing *a to get back to the array sum += v } return } // Output: The sum of the array is: 24.600000