$a &= $b      $a = $a & $b      Bitwise And
$a |= $b      $a = $a | $b      Bitwise Or
$a ^= $b      $a = $a ^ $b      Bitwise Xor
$a <<= $b     $a = $a << $b     Left shift
$a >>= $b     $a = $a >> $b     Right shift