So I'm using a session under https://mywebsite.com
If I redirect via a hyperlink to https://www.mywebsite.com the session does not show.
Why does the www make a difference?
$_SESSION not working without www.
You'll need to use session_set_cookie() and set the 3rd argument to ".mywebsite.com" (note leading dot). See https://www.php.net/manual/en/session.configuration.php#ini.session.cookie-domain for more info.
What you really need to do is pick a URL scheme and then use mod rewrite to enforce it. Choose either one, it doesn't matter. Do not allow both.
7 days later
It might help to review some of the basics of cookies. One of the fundamental concepts with cookies is that they are associated with a specific domain. Note that mywebsite.com and www.mywebsite.com are not identical domains -- the latter is a subdomain of the former. There are security considerations for cookies. For example, you wouldn't want one website to have access to cookies from another website. If that were allowed, a bad guy, e.g., badwebsite.com, might see cookies for gmail.com, thereby gaining access to your email.
18 days later
