To address the first part of your question, it looks like you're making the mistake of confusing definedness with emptiness. Something is defined if it has a value. Something is true if the value meets Perl's definition of true.(i.e., anything that isn't zero or the empty string)

In your case, if you need to differentiate a value of zero from no entry at all, you can do this: 

my $value = param(value);

print "No answer" if ($value eq "");
print "There's an answer, but it's zero" if ($value eq 0);

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Gary Blackburn
Trained Killer

In reply to Re: zero vs. empty by Trimbach
in thread zero vs. empty by gwhite

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