- array_map: documentation ( source)
- filter_var: documentation ( source)
- print_r: documentation ( source)
<?php
$_POST['site'] = [1, 2, 3, '4foo', '5bar'];
$sites = array_map(function ($val) {
return filter_var($val, FILTER_SANITIZE_NUMBER_INT);
}, $_POST['site']);
print_r($sites);