3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = ['4149','8397','9652','4378','3199','7999','8431','5349','7068']; var_export(preg_grep('/(.).*\1/', $array, PREG_GREP_INVERT));
Output for 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.13
array ( 1 => '8397', 2 => '9652', 3 => '4378', 6 => '8431', 7 => '5349', 8 => '7068', )
preferences:
78.78 ms | 406 KiB | 5 Q