How to add url parameter to the current url?

Question

Currently I'm at

http://example.com/topic.php?id=14  

and I want to make a link to

http://example.com/topic.php?id=14&like=like  

by not defining the current url. Like <a href="&like=like">Like</a>. However this last one shows me http://example.com/&like=like

Answer 1

There is no way to write a relative URI that preserves the existing query string while adding additional parameters to it.

You have to:

topic.php?id=14&like=like 

Answer 2

function currentUrl() {     $protocol = strpos(strtolower($_SERVER['SERVER_PROTOCOL']),'https') === FALSE ? 'http' : 'https';     $host     = $_SERVER['HTTP_HOST'];     $script   = $_SERVER['SCRIPT_NAME'];     $params   = $_SERVER['QUERY_STRING'];      return $protocol . '://' . $host . $script . '?' . $params; } 

Then add your value with something like;

echo currentUrl().'&value=myVal';