Quick question about bitwise operators...

[crptcblade]

I know you 'or' things together when using style masks and stuff, so how do you determine if a value has been 'or'ed into the resulting value.

Like:

long a;
a = 9 | 3;

so later on in the app, how do I determine that a contains 9?

[MXK]

From what I can see - you can't.

The result of 9|3=11
That could have also come from
10|1
9|2
10|3

and that can keep on going. Now, you can technically figure out that this result contains a 9 by saying 11 & 9 - that would return 9 indicating that it does exist in this value, but you can't figure out if that was the actual number used to get 11.

[Zaei]

That is why you use powers of two when setting flags... 1, 2, 4, 8, 16, 32, etc.

Z.

[crptcblade]

Originally posted by Zaei
That is why you use powers of two when setting flags... 1, 2, 4, 8, 16, 32, etc.

Z.

That makes sense. Thanks.