<html><body>$url = "../index.html";// Remove all illegal characters from a url$url = filter_var($url, FILTER_SANITIZE_URL);// Validate urlif (!filter_var($url, FILTER_VALIDATE_URL) === false) { echo("$url is a valid URL");} else { echo("$url is not a valid URL");}</body><!-- Mirrored from www.w3schools.com/php/phptryit.asp?filename=tryphp_filter7 by HTTrack Website Copier/3.x [XR&CO'2014], Mon, 27 Jan 2020 02:29:33 GMT --></html>