Re: Why won`t this work??
| From: | bard | Date: | Sun, 21 Jan 2001 12:10:17 +0000 |
| Subject: | Re: Why won`t this work?? | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-35891@lists.php.net to get a copy of this message | ||
On Sun, 21 Jan 2001, Alexander Wagner wrote:
> Website4S@aol.com wrote:
> > Hi,
> >
> > Can anyone tell me before I rip my hair out, why this won`t work??
> >
> > if (!UN)
> > {
> > printf("<SCRIPT LANGUAGE='JAVASCRIPT'>alert('Please enter a User
> > Name.');self.history.back();</SCRIPT>");
> > }
> >
> > TIA
> > Ade
>
> An undefined constant will return true. You have to explicitly define
> it as 0 to make this work.
> I guess this is becauese PHP interpretes it as a string, and all
> strings but '' are true. It has to, because it doesn't know it is a
> constant.
>
> Wagner
>
Plus, this is PHP, not javascript. Variables look like this, "$UN" not this,
"UN".
Brad