C# Iterating through an enum? (Indexing a System.A

Question

I have the following code:

// Obtain the string names of all the elements within myEnum 
String[] names = Enum.GetNames( typeof( myEnum ) );

// Obtain the values of all the elements within myEnum 
Array values = Enum.GetValues( typeof( myEnum ) );

// Print the names and values to file
for ( int i = 0; i < names.Length; i++ )
{
    print( names[i], values[i] ); 
}

However, I cannot index values. Is there an easier way to do this?

Or have I missed something entirely!

Answer 1

You can cast that Array to different types of Arrays:

myEnum[] values = (myEnum[])Enum.GetValues(typeof(myEnum));

or if you want the integer values:

int[] values = (int[])Enum.GetValues(typeof(myEnum));

You can iterate those casted arrays of course :)

Answer 2

How about a dictionary list?

Dictionary<string, int> list = new Dictionary<string, int>();
foreach( var item in Enum.GetNames(typeof(MyEnum)) )
{
    list.Add(item, (int)Enum.Parse(typeof(MyEnum), item));
}

and of course you can change the dictionary value type to whatever your enum values are.

Answer 3

You can simplify this using format strings. I use the following snippet in usage messages:

writer.WriteLine("Exit codes are a combination of the following:");
foreach (ExitCodes value in Enum.GetValues(typeof(ExitCodes)))
{
    writer.WriteLine("   {0,4:D}: {0:G}", value);
}

The D format specifier formats the enum value as a decimal. There's also an X specifier that gives hexadecimal output.

The G specifier formats an enum as a string. If the Flags attribute is applied to the enum then combined values are supported as well. There's an F specifier that acts as if Flags is always present.

See Enum.Format().

Answer 4

In the Enum.GetValues results, casting to int produces the numeric value. Using ToString() produces the friendly name. No other calls to Enum.GetName are needed.

public enum MyEnum
{
    FirstWord,
    SecondWord,
    Another = 5
};

// later in some method  

 StringBuilder sb = new StringBuilder();
 foreach (var val in Enum.GetValues(typeof(MyEnum))) {
   int numberValue = (int)val;
   string friendyName = val.ToString();
   sb.Append("Enum number " + numberValue + " has the name " + friendyName + "\n");
 }
 File.WriteAllText(@"C:\temp\myfile.txt", sb.ToString());

 // Produces the output file contents:
 /*
 Enum number 0 has the name FirstWord
 Enum number 1 has the name SecondWord
 Enum number 5 has the name Another
 */

Answer 5

Here is a simple way to iterate through your custom Enum object

For Each enumValue As Integer In [Enum].GetValues(GetType(MyEnum))

     Print([Enum].GetName(GetType(MyEnum), enumValue).ToString)

Next

Answer 6

You need to cast the array - the returned array is actually of the requested type, i.e. myEnum[] if you ask for typeof(myEnum):

myEnum[] values = (myEnum[]) Enum.GetValues(typeof(myEnum));

Then values[0] etc