Editing Mask (computing) (section)

===Querying the status of a bit===
It is possible to use bitmasks to easily check the state of individual bits regardless of the other bits. To do this, turning off all the other bits using the bitwise <code>AND</code> is done as discussed above and the value is compared with <code>0</code>. If it is equal to <code>0</code>, then the bit was off, but if the value is any other value, then the bit was on. What makes this convenient is that it is not necessary to figure out what the value actually is, just that it is not <code>0</code>.

Example: Querying the status of the 4th bit
     1001'''1'''101   1001'''0'''101
 AND 0000'''1'''000   0000'''1'''000
   = 0000'''1'''000   0000'''0'''000