How do I delete a cookie from a specific domain using Javascript?

Question

Let's say I am at http://www.example.com and I want to delete a cookie whose domain is .example.com and another one whose domain is www.example.com.

I am currently using this generic function :

var deleteCookie = function (name)
{
  document.cookie = name + '=; path=/; expires=Thu, 01 Jan 1970 00:00:01 GMT;';
};

which only seems to be removing cookies whose domain is www.example.com.

But how can I specify so that it also removes cookies whose domain is .example.com ?

EDIT : Basically I'm looking for a function that can delete all cookies related to http://www.example.com as long as they don't have the httponly flag. Is there such a function?

Answer 1

You could do this only if you were at http://example.com and wanted to delete http://blah.example.com cookie. It wouldn't work from www.example.com either - only the "base" domain can delete subdomain cookies.

There are also "all-subdomain" cookies, which start with a ., and can also only be deleted by the base domain.

From the base domain, this should work to delete it:

document.cookie = 'my_cookie=; path=/; domain=.example.com; expires=' + new Date(0).toUTCString();

Or using the excellent jquery.cookie plugin:

$.cookie('my_cookie',null, {domain:'.example.com'})