PHP会话变量不会取消设置

Question

I have a couple of lines of code in a Drupal module as so:

if ($arg == 'true' && isset($_SESSION['xyz']['noredirect'])) {
    unset($_SESSION['xyz']['noredirect']);
}

When the 2nd line is executed, I get error:

Error messageNotice: Undefined variable: _SESSION in blah() (line 122 of /home/xxxxxxx/public_html/sites/all/modules/blah/blah.module).

I simply cannot understand why if the session is set, I cannot unset it.

Any ideas?

Thanks

Answer 1

It would appear that you are yet to run session_start() . This will create the $_SESSION superglobal.

Answer 2

The module now works exactly as I want it to. I solved it by using session_destroy(); rather than unset. It's probably not the most elegant way of fixing it but it works and I couldn't find any other way to do so.

if ($arg == 'true' && isset($_SESSION['xyz']['noredirect'])) {
session_destroy(); 

}