$a = 9;
$b = 10;
echo $a & $b;
place value 128 64 32 16 8 4 2 1
$a 0 0 0 0 1 0 0 1 =9
$b 0 0 0 0 1 0 1 0 =10
result 8
only bit they share together is the 8 bit. So 8 gets returned.
$a = 36;
$b = 103;
echo $a & $b;
place value 128 64 32 16 8 4 2 1
$a 0 0 1 0 0 1 0 0 =36
$b 0 1 1 0 0 1 1 1 =103
result 32+4 = 36
the only bits these two share together are the bits 32 and 4 which when added together return 36.
$a = 9;
$b = 10;
echo $a | $b;
place value 128 64 32 16 8 4 2 1
$a 0 0 0 0 1 0 0 1 =9
$b 0 0 0 0 1 0 1 0 =10
result 8+2+1 = 11
3 bits set, in the 8, 2, and 1 column.add those up 8+2+1 and you get 11
$a = 9;
$b = 10;
echo $a ^ $b;
place value 128 64 32 16 8 4 2 1
$a 0 0 0 0 1 0 0 1 =9
$b 0 0 0 0 1 0 1 0 =10
result 2+1 = 3
the 2 bit and the 1 bit that they each have set but don't share. Soooo 2+1 = 3
