From: Mark Hubbart <discord@...>
Date: 2004-06-15T07:47:06+09:00
Subject: Re: undefine


On Jun 14, 2004, at 2:58 PM, tony summerfelt wrote:

> while(<binkd>)
> {
>     # date parsing code was here
>      @diff=Delta_DHMS(@binkdate,@today) if /(\[\d+\])/;
>      print $trimmed $_ if $diff[0] < $ARGV[1] && defined(@diff);
>      next  if defined(@diff);
>      print $trimmed $_ if ! /(\[\d+\])/;
>      undef(@diff);
> }

testing whether diff is defined won't work in ruby anyway. Any time you 
have an expression like this:

   foo = 23 if expression

foo ends up being automagically defined anyway. After running that 
code, if expression is false, foo == nil.

So, as Sean says, it would probably be better to use nil, unless 
Delta_DHMS might return nil itself.

cheers,
Mark