3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 3; $b=4; echo "\na ".$a; echo "\nb ".$b; $a ^= $b; echo "\na ".$a; echo "\nb ".$b; $b ^= $a; echo "\na ".$a; echo "\nb ".$b;
based on EUaSG
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.2.0
a 3 b 4 a 7 b 4 a 7 b 3