3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [1, [2, 3]]; $array[1][1] = &$array; count($array, COUNT_RECURSIVE);
based on 3A3Eg
Output for 8.0.0 - 8.0.3
Warning: count(): Recursion detected in /in/DlrWH on line 5
Output for 7.3.0 - 7.3.26, 7.4.0 - 7.4.14
Warning: count(): recursion detected in /in/DlrWH on line 5