If you are looking for get url parameters in php then no need to write any logic or condition for getting it.Php has in built function called as “parse_url” this function return as array with parameter like host,path,query,fragment and more options.For more explanation please refer bellow given example.

  $url = 'http://www.my-php-scripts.net/index.php?arg=value&args2=dfsdfsf#anchor'; 
  print_r($url); 

This will return following

  Array ( 
          [scheme] => http 
          [host] => www.my-php-scripts.net 
          [path] => /index.php 
          [query] => arg=value&args2=dfsdfsf 
          [fragment] => anchor 
) 

If you mean url parameter as logically form then you can use $_GET[‘param_name’] to get it.