Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Can I avoid casting an enum value when I try to use or return it?

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?

like image 830
Mark Carpenter Avatar asked Feb 23 '09 15:02

Mark Carpenter


People also ask

Can you return an enum?

How can I return enums like this? on a sidenote, according to java conventions enums should start with an upper case letter. An enum is a (special type of) class, so you should declare it as the return type of your method. By the way, it would be better to name it Decision (it is a class).

Why is enum not good?

It's hard to voice what your actual needs are to a potential partner for fear that they may write you off. Transparency requires over communication. If your communication skills are already not that great, ENM is going to be more of a headache than an opportunity to be your most authentic self.

Can enum be treated as int?

An Enum value cannot be treated as an int by default because then you would be able to provide any integer and there would be no compile time check to validate that the provided integer does in fact exist as a value in the Enumeration.

Can enum be a return type or function?

enum is a data type, not a function.


1 Answers

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;     } } 
like image 158
Michael Meadows Avatar answered Sep 20 '22 11:09

Michael Meadows