(How)
C^# You Are - 04 February 2007

1. What is the base type of an enumeration?  Answer

   The default base type of an enumeration is Int32.  However it can be any integral type.  You should use Int32 whenever possible since it is the assumed type of an enumeration.

2. How do you retrieve the values defined in an enumeration (programmatically)?  Answer

   The method Enum.GetValues will return the values defined for an enumeration.  This method uses reflection and therefore will be expensive.

3. How do you get the named constants of an enumeration (programmatically)?  Answer

   The method Enum.GetNames will return the named constants for the enumeration values.  As with GetValues this method uses reflection and will be expensive.

4. How do you convert from a string to its enumerated constant value?  Answer

   The method Enum.Parse will convert a string to its enumerated equivalent provided there is a conversion.  The method supports either the numeric value or the named constant.  In both cases it will use reflection to match to the enumerated values.

5. What benefit does enumerations serve anyway?  Answer

   Enumerations provide strong type-checking of a set of constant values.  For example the colors or the keys on a keyboard are fixed.  Using an enumeration type allows us to specify the colors or keys and then ensure that any usage of the type will only use the specified values.  Of course a user could circumvent the type-safety but it would require a type cast.  Refer to System.Drawing.Color and System.Windows.Forms.Keys.