html - 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