How to check if any flags of a flag combination are set?

Question

Let\'s say I have this enum:

[Flags]
enum Letters
{
     A = 1,
     B = 2,
     C = 4,
     AB = A | B,
     All = A | B | C,
}

To check i

Answer 1

How about

if ((letter & Letters.AB) > 0)

?