The point I was making is that what you've "been using", and what you're considering "might be a better choice", use identical logic: the logic is written differently but both achieve the same result.

I've looked long at the condition and TRUE/FALSE code in both but can't see any difference. It's possible I'm missing something: if not, then your not really changing anything and perhaps there's a typo in your posted code.

Greetings kcott, and thank you for the followup.

My rationale (which might be an oxymoron) was that if I didn't have an Accept value (one wasn't provided). the unless would ensure an "always valid" -- see; defined value. No?

I think this speaks volumes on how I think. Kinda' scary. It's so revealing. :)

Thanks again, for taking the time to respond!

--Chris

#!/usr/bin/perl -Tw
use Perl::Always or die;
my $perl_version = (5.12.5);
print $perl_version;

"My rationale (which might be an oxymoron) was that if I didn't have an Accept value (one wasn't provided). the unless would ensure an "always valid" -- see; defined value. No?"

No! And that's very easy to test:

#!/usr/bin/env perl -l

use strict;
use warnings;

my %test_hash;

if ($test_hash{unset_key} =~ /x/) {
    print 'true';
}
else {
    print 'false';
}

unless ($test_hash{unset_key} =~ /x/) {
    print 'false';
}
else {
    print 'true';
}
[download]

Output:

Use of uninitialized value $test_hash{"unset_key"} in pattern match (m
+//) at ./pm_example.pl line 8.
false
Use of uninitialized value $test_hash{"unset_key"} in pattern match (m
+//) at ./pm_example.pl line 15.
false
[download]

Perhaps you want exists and/or defined.

-- Ken