How to check url contains http or htttps in php

Hi with the following code you can get the protocol of the server  

if (isset($_SERVER['HTTPS']) &&
    ($_SERVER['HTTPS'] == 'on' || $_SERVER['HTTPS'] == 1) ||
    isset($_SERVER['HTTP_X_FORWARDED_PROTO']) &&
    $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
  $protocol = 'https://';
}
else {
  $protocol = 'http://';
}