3v4l.org

run code in 300+ PHP versions simultaneously
<?php $string = "hello this is a string and hello but this is a string hello but this is a string and "; if (preg_match_all('~(?=(\b(\w.{9,})(?=.*?\b\2)))~u', $string, $m)) { echo array_reduce($m[1], function ($a, $b) { return strlen($a ?? '') > strlen($b ?? '') ? $a : $b; }); }

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23.54 ms | 402 KiB | 5 Q