Strips all chars which are not 0-9, + and -, but supports some flags as well.

<?php
$flags 
= array(
    
'FILTER_FLAG_ALLOW_FRACTION''FILTER_FLAG_ALLOW_THOUSAND',
    
'FILTER_FLAG_ALLOW_SCIENTIFIC'
);
$filter FILTER_SANITIZE_NUMBER_FLOAT;
include 
'presentations/slides/input-filter/render-form.php';
include 
'presentations/slides/input-filter/check-data.php';
?>
Output
data:
FILTER_FLAG_ALLOW_FRACTION
FILTER_FLAG_ALLOW_THOUSAND
FILTER_FLAG_ALLOW_SCIENTIFIC