PHP - Get Users IP Address

Get Users IP Address 

<?php
class datasource {
 function getIP() {
  $ipaddress = '';
  if (isset($_SERVER['HTTP_CLIENT_IP']))
   $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
  else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']))
   $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
  else if(isset($_SERVER['HTTP_X_FORWARDED']))
   $ipaddress = $_SERVER['HTTP_X_FORWARDED'];
  else if(isset($_SERVER['HTTP_FORWARDED_FOR']))
   $ipaddress = $_SERVER['HTTP_FORWARDED_FOR'];
  else if(isset($_SERVER['HTTP_FORWARDED']))
   $ipaddress = $_SERVER['HTTP_FORWARDED'];
  else if(isset($_SERVER['REMOTE_ADDR']))
   $ipaddress = $_SERVER['REMOTE_ADDR'];
  else
   $ipaddress = 'UNKNOWN';
  return $ipaddress;
 }
}

$clasgetip = new datasource;
$ipaddress = $clasgetip->getIP();
echo $ipaddress;
?>