package main import ( "fmt" "math/rand" "time" ) func main() { // without seeding rand.Intn will always return the same sequence rand.Seed(time.Now().UnixNano()) switch n := rand.Intn(9); n { case 1, 2, 3: fmt.Printf("case 1, 2, 3: n is %d\n", n) case 4, 5: fmt.Printf("case 4, 5: n is %d\n", n) default: fmt.Printf("default: n is %d\n", n) } }