^= means what in PHP language?

[lay3478]

I came across usage of ^= in one the password hashing codes and am trying to find what this operator means in PHP.

[gw1500se]

Syntax error.

[mac_gyver]

it's actual a combined assignment and bitwise Xor (exclusive or). the starting value on the left is Xor'ed with the value on the right and becomes the new value on the left.

[requinix]

Basically every "$x symbol= $y" means "$x = $x symbol $y". So the question is really more about what ^ means.

Convenient list of operators

[gw1500se]

Oops. Apologies. I misread the syntax.

[Barand]

For example

$a = 1010
$b = 1111
$b ^= $a   // Xor
$b = 0101
$b ^= $a   // repeat Xor
$b = 1111  // $b restored

 

[lay3478]

Thanks @Barand

[lay3478]

Thanks everyone.