Test if links are external with jQuery / javascript?

Question

How do I test to see if links are external or internal? Please note:

1. I cannot hard code the local domain.
2. I cannot test for \"http\". I could just as

Answer 1

You forgot one, what if you use a relative path.

forexample: /test

        hostname = new RegExp(location.host);
            // Act on each link
            $('a').each(function(){

            // Store current link's url
            var url = $(this).attr("href");

            // Test if current host (domain) is in it
            if(hostname.test(url)){
               // If it's local...
               $(this).addClass('local');
            }
            else if(url.slice(0, 1) == "/"){
                $(this).addClass('local'); 
            }
            else if(url.slice(0, 1) == "#"){
                // It's an anchor link
                $(this).addClass('anchor'); 
            }
            else {
               // a link that does not contain the current host
               $(this).addClass('external');                        
            }
        });

There are also the issue of file downloads .zip (local en external) which could use the classes "local download" or "external download". But didn't found a solution for it yet.