3v4l.org

run code in 300+ PHP versions simultaneously
<?php function ackermann( $m , $n ) { if ( $m==0 ) { return $n + 1; } elseif ( $n==0 ) { return ackermann( $m-1 , 1 ); } return ackermann( $m-1, ackermann( $m , $n-1 ) ); } echo ackermann( 3, 4 ); ?>
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, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
125
preferences:
227.21 ms | 406 KiB | 330 Q