- var_dump: documentation ( source)
- filter_var: documentation ( source)
- preg_replace: documentation ( source)
<?php
$v = '-';
var_dump((int) $v);
$deactive = preg_replace('/[^a-zA-Z0-9-]/', '', (int) $v);
var_dump($deactive);
var_dump(filter_var($v, FILTER_VALIDATE_INT));