$re = '/^(?![0-9]+$)(?=.*[a-zA-Z])[a-zA-Z0-9]+$/m';
$str = 'admin
l0v3y0oplj
123admin
123ADMIN?
123ADMIN
am.ouy?
12345678909776apouatgb
1ads967bjk
ADMIN123
123
,;/.;..,,;.#$¨$#¨%
!@#$%3333333333333333333332';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php