Simple function to prepare URL's with either http or https

prepare-url.php

<?php
function prepare_url($string) {

  //Check if the string starts with http or https
  if (substr($string, 0, 7) == "http://" OR substr($string, 0, 8) == "https://") {
    $url = $string;
    
  } else {
    //Remove any presence of http:// or https:// from the link
    $string = str_replace("://", "", $string);
    $string = str_replace("https", "", $string);
    $string = str_replace("http", "", $string);
    
    //Parse the url and see if t returns with a secured url
    $url_check = parse_url($string);
    if($url_check['scheme'] == 'https'){
      $url = 'https://'.$string;
    } else {
      $url = 'http://'.$string;
    }
  }
  return $url;
}

?>