In PHP, using $_COOKIE to retrieve the value of a newly created cookie immediately after calling setcookie() can result in the desired value being unavailable. This phenomenon arises from the asynchronous nature of HTTP cookie handling.
When setcookie() is invoked, the PHP script issues a command to create a cookie and include it in the outgoing HTTP response. However, the response is not sent to the client (i.e., the browser) until the script completes its execution.
As the $_COOKIE variable reflects the cookies included in the current HTTP request, any changes made to cookies during the execution of the server-side script are not immediately available in $_COOKIE.
To illustrate the timeline:
To ensure $_COOKIE reflects the newly set cookie value, you can override it within the same script:
setcookie('uname', $uname, time() + 60 * 30); $_COOKIE['uname'] = $uname;
This action creates the cookie in the outgoing HTTP response and immediately sets its value in the $_COOKIE variable, making it accessible for use within the current script execution.
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