about session_is_registered

[virva]

How do I check if the session variable userid is not registered? Is this the right syntax?

if (!session_is_registered(userid)) {

//then do something

}

Thanks if you can help.

[intenz]

NO and again NO!
Do not use session_is_registered();

Use...

if(!$_SESSION['userid'])
{
     echo 'userid is not registered';
}
else
{
     echo 'userid is registered';
}

[Weedpacket]

Better would be

!isset($_SESSION['userid'])

- a session variable might be set to the value 0, in which case !$_SESSION['variable'] would give the wrong result. May not be relevant in this case (is there a User Zero?) but where's the percentage in being a boy racer?

The only irritating thing about setting/unsetting session variables through the $SESSION array seems to be some sort of (de)referencing bug (which has been logged). unset($SESSION['var']); doesn't work; one has to go $_SESSION['var']=null; instead.