From: Robert Klemme <bob.news@...>
Date: 2004-07-05T16:37:41+09:00
Subject: Re: How to detect if variable has been defined yet?


"Randy Lawrence" <jm@zzzzzzzzzzzz.com> schrieb im Newsbeitrag
news:JJhFc.31726$eH1.15066611@newssvr28.news.prodigy.com...
> Sean O'Dell wrote:
>
> > On Friday 02 July 2004 10:49, Randy Lawrence wrote:
> >
> >>Hi,
> >>
> >>I'd like to detect if a variable has been defined yet.  Is this
possible
> >>in Ruby or mod_ruby?
> >>
> >>For example, I'd like to do the following:
> >>
> >>if $total.exists
> >>    $total = $total + 1
> >>else
> >>    $total = 0
> >>end
> >
> >
> > if defined?($total)
> >     $total = $total + 1
> > else
> >     $total = 0
> > end
> >
> >
> > Sean O'Dell
> >
> >
>
> Thanks! This was exactly what was needed and it works.

Just an additional note: from runtime performance it is much more
efficient to first initialize a variable and then use it.  The code looks
cleaner then, too.

$total = 0
....

some loop
  $total += 1
end

Regards

    robert