枚举是一组命名的整数常量.
在F＃中，枚举，也称为枚举，是不可或缺的将标签分配给值的子集的类型.您可以使用它们代替文字来使代码更具可读性和可维护性.
声明枚举的一般语法是 :
type enum-name = | value1 = integer-literal1 | value2 = integer-literal2 ...
以下示例演示了枚举与减号的使用;
// Declaration of an enumeration. type Days = | Sun = 0 | Mon = 1 | Tues = 2 | Wed = 3 | Thurs = 4 | Fri = 5 | Sat = 6 // Use of an enumeration. let weekend1 : Days = Days.Sat let weekend2 : Days = Days.Sun let weekDay1 : Days = Days.Mon printfn "Monday: %A" weekDay1 printfn "Saturday: %A" weekend1 printfn "Sunday: %A" weekend2
当你编译并执行程序，它产生以下输出 :
Monday: Mon Saturday: Sat Sunday: Sun
