- var_dump: documentation ( source)
- preg_grep: documentation ( source)
- array_diff: documentation ( source)
<?php
$arr = ["!qwerty","sapien", "!Bart", "!qwerty", "aa!bb"];
$filtered = preg_grep("/^\!.*$/", $arr);
Var_dump($filtered);
var_dump(array_diff($arr, $filtered));