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

There are two aproaches that I can see that would work for checking for any bit being set.

Aproach A

if (letter != 0)
{
}

This works as long as you don't mind checking for all bits, including non-defined ones too!

Aproach B

if ((letter & Letters.All) != 0)
{
}

This only checks the defined bits, as long as Letters.All represents all of the possible bits.

For specific bits (one or more set), use Aproach B replacing Letters.All with the bits that you want to check for (see below).

if ((letter & Letters.AB) != 0)
{
}