ActionScript 3: Bitwise Flags

Bitwise flags are used in the Alert component in flash for example. The show method expects the button options: Alert.OK | Alert.CANCEL for example.

Each of this properties have a uint value (bit value to be exact), smth like this for example:
public const OK:uint = 1; public const CANCEL:uint = 2; public const YES:uint = 4; public const NO:uint = 8;

Remember they are bit values, that's why i don't use a perfect numerical increment.

Check out this example:
// let's add the YES and NO flags public var flags:uint = YES | NO; // this is the same as doing the following: // flags |= YES; // flags |= NO;

Now in order to check if a flag has been set:
if((flags & YES) == YES) trace ("YES flag is set"); if((flags & NO) == NO) trace ("NO flag is set"); if((flags & OK) == OK) trace ("OK flag is set"); // the way i always do this is the following because if the flag exists it will return a // number different than 0 // if(flags & YES) trace ("YES flag is set");

Now, how do we unset a flag? Easy!
// remove the NO flag flags ^= NO; if(flags & NO) trace ("NO flag is set"); // No trace so successfully unset! :)

Hope this helps you somehow :)

--fernando