I need validate when exists negative numbers in the list.
I think the better way do this is using regex.
func main() {
fmt.Println(add("-1\n,2,3"))
}
func add(numbers string) int {
re := regexp.MustCompile("[0-9]+")
sum := 0
for _, i := range re.FindAllString(numbers, -1) {
number, _ := strconv.Atoi(i)
sum += number
}
return sum
}