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====== Chess - Programming - Bit Operations ======

^Expression^Description^Example^
|x & y|AND the bits of x with those of y|21 & 7 = 10101 & 00111 = 00101 = 5|
|x <nowiki>|</nowiki> y|OR the bits of x with those of y|21 <nowiki>|</nowiki> 7 = 10101 <nowiki>|</nowiki> 00111 = 10111 = 23|
|x <nowiki>^</nowiki> y|XOR the bits of x with those of y|21 <nowiki>^</nowiki> 7 = 10101 <nowiki>^</nowiki> 00111 = 10010 = 18|
|~x|Inverting (complementing) the bits of x (0 -> 1 and 1 -> 0)|~7 = 11111111111111000 = 65528|
|x << y|Shift the bits of x to the left y positions|25 << 3 = 10101 << 3 = 10101000 = 168|
|x >> y|Shift the bits of x to the right y positions|25 >> 3 = 10101 >> 3 = 00010 = 2|

----

===== Get only even or odd bits =====

Take a number, say 12345678.

  * In Binary, this is 00000000101111000110000101001110.

Apply an even mask against it:

<code>
00000000101111000110000101001110   &    (n)
10101010101010101010101010101010        (0xAAAAAAAA)
————————————————————————————————
00000000101010000010000000001010        (Contains all even bits)
</code> 

Apply an odd mask against it:

<code>
00101101011001010111000110001001   &    (n)
01010101010101010101010101010101        (0x55555555)
————————————————————————————————
00000000000101000100000101000100        (Contains all odd bits)
</code> 

<WRAP info>
**NOTE:**  Use Masks.

  * Mask **0xAAAAAAAA** has all its even bits set.
    * Its bitwise AND with a number will separate out the even bits.
    * 1010 1010 1010 1010 1010 1010 1010 1010

  * Mask **0x55555555** has all its odd bits set.
    * Its bitwise AND with a number will separate out the odd bits.
    * 1010 1010 1010 1010 1010 1010 1010 1010

</WRAP>

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