How to delete/unset a cookie on php?

Question

I want to unset/delete my existing cookie with this:

setcookie (\"user\", \"\", time()-1); 
unset($user);

But cookies can not be deleted or

Answer 1

As already was said - when deleting a cookie you should assure that the expiration date is in the past.

BUT you also have to use the same path and even domain for deleting, which you used for cookie creating, so if create cookie like this

setcookie ("user", "John", time()+7200, '/', 'mydomain.com'); 

to delete this cookie use this code

setcookie ("user", "", time()-3600, '/', 'mydomain.com');

and also better use specific date in the past instead of time() - 3600