how to sanitize php code example

Example 1: sanitize form data php

# sanitize form data
function clean($data)
{
    $data = htmlspecialchars($data);
    $data = stripslashes($data);
    $data = trim($data);
    return $data;
}

Example 2: sanitize user input php

<?php
function sanitize($string) {
	return addslashes(htmlspecialchars($string));
}
?>