3v4l.org

run code in 300+ PHP versions simultaneously
<?php $test = 'a@z'; $test++; echo $test; echo "\n"; $test = 'a0z'; $test++; echo $test;
Output for 8.3.0 - 8.3.6
Deprecated: Increment on non-alphanumeric string is deprecated in /in/AtQAK on line 2 a@a a1a
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18
a@a a1a

preferences:
235.06 ms | 405 KiB | 383 Q