3v4l.org

run code in 300+ PHP versions simultaneously
<?php for($i = 1; $i <= 20; $i += 4){ echo $i . ', '; }
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
1, 5, 9, 13, 17,

preferences:
204.75 ms | 403 KiB | 283 Q