How can examining HTTP headers help troubleshoot cookie management issues in PHP?

Examining HTTP headers can help troubleshoot cookie management issues in PHP by allowing you to see the cookies being set and sent by the server. This can help identify if the correct cookies are being set, if they are being overwritten, or if they are not being sent back to the server on subsequent requests.

// Output all HTTP headers to see if cookies are being set correctly
$headers = getallheaders();
print_r($headers);