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<!DOCTYPE html> <html> <body> <?php $url = "../index.html"; // Remove all illegal characters from a url $url = filter_var($url, FILTER_SANITIZE_URL); // Validate url if (!filter_var($url, FILTER_VALIDATE_URL) === false) { echo("$url is a valid URL"); } else { echo("$url is not a valid URL"); } ?> </body> </html>
https://www.w3schools.com is a valid URL