Switch

Go

package main
 
import (
    "fmt"
    "strconv"
)
 
func str2int(s string) int {
    i, err := strconv.Atoi(s)
    if err != nil {
        panic("Not a number")
    }
    return i
}
func main() {
    var number_string string
    fmt.Scanln(&number_string)
    number := str2int(number_string)
 
    switch number {
    case 8:
        fmt.Println("Oxygen")
    case 1:
        fmt.Println("Hydrogen")
    case 2:
        fmt.Println("Helium")
    case 11:
        fmt.Println("Sodium")
    default:
        fmt.Printf("I have no idea what %d is\n", number)
 
    // Alternative solution
 
    fmt.Scanln(&number_string)
    db := map[int]string{
        1:  "Hydrogen",
        2:  "Helium",
        8:  "Oxygen",
        11: "Sodium",
    }
    number = str2int(number_string)
    if name, exists := db[number]; exists {
        fmt.Println(name)
    } else {
        fmt.Printf("I have no idea what %d is\n", number)
    }
}