go 언어 func main()

package main
import "fmt"
func summation(val1 int, val2 int) (summation_result int) {
   summation_result = val1+ val2
   return
}
func subtraction(val1 int, val2 int) (subtraction_result int) {
   subtraction_result = val1 - val2
   return //subtraction_result
}
func multiplication(val1 int, val2 int) (multiplication_result int) {
   multiplication_result = val1 * val2
   return //multiplication_result
}
func dividen(val1 int, val2 int) (dividen_result float32) {
   dividen_result = float32(val1) /float32(val2)
   return     //dividen_result
}
func main() {
   var val_left int
   var val_right int

   fmt.Print("val_left is  ")
   fmt.Scanf("%d", &val_left)

   fmt.Print("val_right is  ")
   fmt.Scanf("%d", &val_right)

   fmt.Printf("%2d + %2d = %2d\n",
      val_left, val_right, summation(val_left, val_right))
   fmt.Printf("%2d - %2d = %2d\n",
      val_left, val_right, subtraction(val_left, val_right))
   fmt.Printf("%2d * %2d = %2d\n",
      val_left, val_right, multiplication(val_left, val_right))
   fmt.Printf("%2d / %2d = %f\n",
      val_left,val_right, dividen(val_left, val_right))
}