Surely an empty string is == false.

In fact I'd be interested if anyone can come up with a situation where  !$x
doesn't return the same as empty($x)

i.e. can anyone get a value of $x such that !$x !== empty($x) 

Tim Ward
Internet Chess www.chessish.com <http://www.chessish.com> 

        ----------
        From:  Kevin Stone [SMTP:[EMAIL PROTECTED]]
        Sent:  07 March 2002 23:56
        To:  'David Johansen'; [EMAIL PROTECTED]
        Subject:  RE: [PHP] Re: User accounts

        I understand your confusion.  The thing is that empty() and ! are
two
        completely different arguments.

        if(empty($var)) is looking for: $var = '';

        if(!$var) is looking for: $var = false; or $var = 0;

        If $var is set to anything other than 0 or false then the ASCII
value of
        the string is (by definition) equivilant to an integer value of 1 or
        more.  And thus is interpreted as true.

        Hope that helps.

        -Kevin

        -----Original Message-----
        From: David Johansen [mailto:[EMAIL PROTECTED]] 
        Sent: Thursday, March 07, 2002 3:44 PM
        To: [EMAIL PROTECTED]
        Subject: [PHP] Re: User accounts

        Here's a little piece of code that gives me a weird problem:

        <?php
        if (!$logout)
        {
           if ($_SESSION['loggedin'])
           {
              unset($_SESSION['loggedin']);
           }
        }
        ?>


        I have the session started and everything, but it gives me the
following
        error.
        Warning: Undefined variable: logout in
c:\inetpub\wwwroot\uslogin.php on
        line 13
        I've seen this used on several examples. I know that if I just use
        empty($logout) then it'll work ok, but I just wanted to know why
it's
        used
        in so many examples but doesn't work in my code. Is there some
setting
        that
        I have set wrong or something? Thanks,
        Dave

        "David Johansen" <[EMAIL PROTECTED]> wrote in message
        [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
        > I'm new to this php thing and I would like to set up a web page
were
        the
        > users can login and edit their preferences and all that stuff. I
have
        the
        > basic login stuff worked out and I was passing the username and
        password
        as
        > a hidden input in the form, but then the password can be seen with
        view
        > source. I know that there's a better way to do this, so could
someone
        point
        > me to a good tutorial or example on how I could make it so that
the
        user
        > could login and logout and then I wouldn't need to be passing the
        password
        > all around like this. Thanks,
        > Dave
        >
        >



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