Bitwise Operators

Bitwise operators allow you to turn specific bits within an integer on or off. If both the left- and right-hand parameters are strings, the bitwise operator will operate on the characters in this string.

<?php
    echo 12 ^ 9; // Outputs '5'

    echo "12" ^ "9"; // Outputs the Backspace character (ascii 8)
                     // ('1' (ascii 49)) ^ ('9' (ascii 57)) = #8

    echo "hallo" ^ "hello"; // Outputs the ascii values #0 #4 #0 #0 #0
                            // 'a' ^ 'e' = #4
?>

Table 11-3. Bitwise Operators

Example	Name	Result
$a & $b	And	Bits that are set in both $a and $b are set.
$a \| $b	Or	Bits that are set in either $a or $b are set.
$a ^ $b	Xor	Bits that are set in $a or $b but not both are set.
~ $a	Not	Bits that are set in $a are not set, and vice versa.
$a << $b	Shift left	Shift the bits of $a $b steps to the left (each step means "multiply by two")
$a >> $b	Shift right	Shift the bits of $a $b steps to the right (each step means "divide by two")