3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 1; $b = &$a; echo (++$a)+(++$a); ?>
Output for 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
5
Output for 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28
6

preferences:
148.32 ms | 402 KiB | 255 Q