Question

If I have the following enum:

public enum ReturnValue{     Success = 0,     FailReason1 = 1,     FailReason2 = 2     //Etc... } 

Can I avoid casting when I return, like this:

public static int main(string[] args){     return (int)ReturnValue.Success; } 

If not, why isn’t an enum value treated as an int by default?

Answer 1

enums are supposed to be type safe. I think they didn’t make them implicitly castable to discourage other uses. Although the framework allows you to assign a constant value to them, you should reconsider your intent. If you primarily use the enum for storing constant values, consider using a static class:

public static class ReturnValue {     public const int Success = 0;     public const int FailReason1 = 1;     public const int FailReason2 = 2;     //Etc... } 

That lets you do this.

public static int main(string[] args){     return ReturnValue.Success; } 

EDIT

When you do want to provide values to an enum is when you want to combine them. See the below example:

[Flags] // indicates bitwise operations occur on this enum public enum DaysOfWeek : byte // byte type to limit size {     Sunday = 1,     Monday = 2,     Tuesday = 4,     Wednesday = 8,     Thursday = 16,     Friday = 32,     Saturday = 64,     Weekend = Sunday | Saturday,     Weekdays = Monday | Tuesday | Wednesday | Thursday | Friday } 

This enum can then be consumed by using bitwise math. See the below example for some applications.

public static class DaysOfWeekEvaluator {     public static bool IsWeekends(DaysOfWeek days)     {         return (days & DaysOfWeek.Weekend) == DaysOfWeek.Weekend;     }      public static bool IsAllWeekdays(DaysOfWeek days)     {         return (days & DaysOfWeek.Weekdays) == DaysOfWeek.Weekdays;     }      public static bool HasWeekdays(DaysOfWeek days)     {         return ((int) (days & DaysOfWeek.Weekdays)) > 0;     }      public static bool HasWeekendDays(DaysOfWeek days)     {         return ((int) (days & DaysOfWeek.Weekend)) > 0;     } }