3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = "test1"; $b = "test2"; $a = $a ^ $b; $b = $a ^ $b; $a = $a ^ $b; echo "a = $a; b = $b";
based on Ubhug
Output for 4.3.0 - 7.2.0
a = test2; b = test1