Modifying a Cookie

The value of a cookie can be modified by resetting the cookie

setcookie("user", "John", time() + 86400, "/"); // assuming there is a "user" cookie already

Cookies are part of the HTTP header, so setcookie() must be called before any output is sent to the browser.

When modifying a cookie make sure the path and domain parameters of setcookie() matches the existing cookie or a new cookie will be created instead.

The value portion of the cookie will automatically be urlencoded when you send the cookie, and when it is received, it is automatically decoded and assigned to a variable by the same name as the cookie name