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 e         


        

Answer 1

Since enums can be declared with multiple primitive types, a generic extension method to cast any enum type can be useful.

enum Box
{
    HEIGHT,
    WIDTH,
    DEPTH
}

public static void UseEnum()
{
    int height = Box.HEIGHT.GetEnumValue<int>();
    int width = Box.WIDTH.GetEnumValue<int>();
    int depth = Box.DEPTH.GetEnumValue<int>();
}

public static T GetEnumValue<T>(this object e) => (T)e;

Answer 2

If you want to get an integer for the enum value that is stored in a variable, for which the type would be Question, to use for example in a method, you can simply do this I wrote in this example:

enum Talen
{
    Engels = 1, Italiaans = 2, Portugees = 3, Nederlands = 4, Duits = 5, Dens = 6
}

Talen Geselecteerd;    

public void Form1()
{
    InitializeComponent()
    Geselecteerd = Talen.Nederlands;
}

// You can use the Enum type as a parameter, so any enumeration from any enumerator can be used as parameter
void VeranderenTitel(Enum e)
{
    this.Text = Convert.ToInt32(e).ToString();
}

This will change the window title to 4, because the variable Geselecteerd is Talen.Nederlands. If I change it to Talen.Portugees and call the method again, the text will change to 3.

Answer 3

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.

Answer 4

The example I would like to suggest "to get an 'int' value from an enum", is

public enum Sample
{
    Book = 1, 
    Pen = 2, 
    Pencil = 3
}

int answer = (int)Sample.Book;

Now the answer will be 1.