Go (golang) enum

enum.go

package main

import "fmt" // for demo, below

type Weekday int

const (
	Sunday Weekday = iota
	Monday
	Tuesday
	Wednesday
	Thursday
	Friday
	Saturday
)

// String is used by formatting functions; i.e., `fmt.Println(w)` automatically runs `fmt.Println(w.String)`
func (w Weekday) String() string {
	return [7]string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}[w]
}

// EnumIndex returns the int value
func (w Weekday) EnumIndex() int {
	return int(w)
}

func main() {
	var x = Sunday
	fmt.Println(x)             // Output : Sunday
	fmt.Println(x.String())    // Output : Sunday
	fmt.Println(x.EnumIndex()) // Output : 0
}