3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 'X'; $b = 'Y'; $c = 'Z'; echo $a.$b.$c;
based on MrgFB
Output for 7.3.0 - 7.3.27, 7.4.0 - 7.4.15, 8.0.0 - 8.0.2
XYZ