Question

IN php, how do the following operands work?

^
|

e.g. $a = 11;
$b = 7;
echo $a ^ $b;

outputs 12

and

    $a =    11;
$b =    7;
echo $a | $b;

outputs 15

Im not sure why in each case. Can someone please shed some light?

Answer 1

Those are bitwise XOR and OR.

$a = 11; // 1011
$b =  7; // 0111

With XOR each bit that is different in $a and $b becomes a 1, the bits that are the same become a 0.

$a ^ $b: // 1100 = 12

With OR each bit that is a 1 in either $a or $b becomes a 1, in this case all the bits.

$a | $b: // 1111 = 15

There is also an AND equivalent: $a & $b: // 0011 = 3

A full list of PHP’s bitwise operators.