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<?php function is_cyclic(&$array) { $isRecursive = false; set_error_handler(function ($errno, $errstr) use (&$isRecursive) { $isRecursive = $errno === E_WARNING && mb_stripos($errstr, 'recursion'); }); try { count($array, COUNT_RECURSIVE); } finally { restore_error_handler(); } return $isRecursive; } $array = [1, [2, 3]]; $array[1][1] = &$array; var_dump(is_cyclic($array));
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.13
bool(true)

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76.16 ms | 406 KiB | 5 Q