Question

I have a MySQL result that I want to safely output using PHP, i.e. converting special characters such as < to <.

filter_var_array works fine, except that NULL values turn into empty string ''.

I still want them to be NULL in order to reflect the MySQL value and to test with is_null() etc.

$sql_rows = filter_var_array($sql_rows, FILTER_SANITIZE_FULL_SPECIAL_CHARS);
foreach ($sql_rows as $sql_row) {
    print '<li>' . $sql_row['name'] . '</li>';
}

Any convenient way to achieve this?

Answer 1

$sql_rows = array_map(function($val){
    return is_null($val) ? null : filter_var($val, FILTER_SANITIZE_FULL_SPECIAL_CHARS);
}, $sql_rows);