isset($_SESSION[]) vs (!$_SESSION[])

[ethought]

Is there any advantage to using or not using the following code

if (!isset($_SESSION['var']))
{
    //Do stuff here
}

Verses this code

if (!$_SESSION['var'])
{
   //Code goes here
}

I have tried both and they both do the same thing from what I can tell.

Thanks.

[LordShryku]

Not using isset() with newer versions of PHP with throw a notice of "undefined blah blah blah". Nothing that will stop your script from running(depending on your error_reporting), but good coding standards will tell you to use isset().

[ethought]

Thanks. I like good coding standards. I wasn't sure if isset() was still good practise or not anyway, so you cleared that up as well.

Thanks again.