3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a=1; $b=&$a; $c=(++$a)+(++$a)+(++$a); echo $c;
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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
9
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.28
10

preferences:
171.08 ms | 401 KiB | 235 Q