Enumeration Values That Set Combinations of Flags

When defining a enum type consisting of a set of flags, you normally add values limited to powers of two.  You can also add values that represent combinations of flags.  These can be used as a shortcut for setting several flags using a single value.

Here’s an example where we define several composite values.

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[Flags] public enum Talents {     Singing = 1,     Dancing = 2,     SongAndDance = Singing | Dancing,     Juggling = 4,     JokeTelling = 8,     DoesItAll = SongAndDance | Juggling | JokeTelling };

Now we can use these composite values when setting flags.

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Talents fred = Talents.Singing | Talents.Dancing; Talents sammy = Talents.SongAndDance;           // Same as Fred Talents eddie = Talents.Singing | Talents.Dancing | Talents.Juggling; Talents bobHope = Talents.DoesItAll;

The ToString method is also smart enough to list out the composite values, rather than the individual flags.

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Console.WriteLine(fred);       // SongAndDance Console.WriteLine(sammy);      // SongAndDance Console.WriteLine(eddie);      // SongAndDance, Juggling Console.WriteLine(bobHope);    // DoesItAll

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