Get int value from enum in C#
Get int value from enum in C#
Question
I have a class called Questions
(plural). In this class there is an enum called Question
(singular) which looks like this.
public enum Question
{
Role = 2,
ProjectFunding = 3,
TotalEmployee = 4,
NumberOfServers = 5,
TopBusinessConcern = 6
}
In the Questions
class I have a get(int foo)
function that returns a Questions
object for that foo
. Is there an easy way to get the integer value off the enum so I can do something like this Questions.Get(Question.Role)
?
Accepted Answer
Just cast the enum, e.g.
int something = (int) Question.Role;
The above will work for the vast majority of enums you see in the wild, as the default underlying type for an enum is int
.
However, as cecilphillip points out, enums can have different underlying types.
If an enum is declared as a uint
, long
, or ulong
, it should be cast to the type of the enum; e.g. for
enum StarsInMilkyWay:long {Sun = 1, V645Centauri = 2 .. Wolf424B = 2147483649};
you should use
long something = (long)StarsInMilkyWay.Wolf424B;
Read more... Read less...
Since Enums can be any integral type (byte
, int
, short
, etc.), a more robust way to get the underlying integral value of the enum would be to make use of the GetTypeCode
method in conjunction with the Convert
class:
enum Sides {
Left, Right, Top, Bottom
}
Sides side = Sides.Bottom;
object val = Convert.ChangeType(side, side.GetTypeCode());
Console.WriteLine(val);
This should work regardless of the underlying integral type.
Declare it as a static class having public constants:
public static class Question
{
public const int Role = 2;
public const int ProjectFunding = 3;
public const int TotalEmployee = 4;
public const int NumberOfServers = 5;
public const int TopBusinessConcern = 6;
}
And then you can reference it as Question.Role
, and it always evaluates to an int
or whatever you define it as.
Question question = Question.Role;
int value = (int) question;
Will result in value == 2
.
On a related note, if you want to get the int
value from System.Enum
, then given e
here:
Enum e = Question.Role;
You can use:
int i = Convert.ToInt32(e);
int i = (int)(object)e;
int i = (int)Enum.Parse(e.GetType(), e.ToString());
int i = (int)Enum.ToObject(e.GetType(), e);
The last two are plain ugly. I prefer the first one.
It's easier than you think - an enum is already an int. It just needs to be reminded:
int y = (int)Question.Role;
Console.WriteLine(y); // Prints 2