3v4l.org

run code in 300+ PHP versions simultaneously
<?php $x = function ($a) { return $a * 2; }; assert( true === is_callable($x) ); assert( 4 == $x(2) );
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.29, 8.0.0 - 8.0.19, 8.1.0 - 8.1.6

preferences:
25.51 ms | 409 KiB | 5 Q