How about trying explicit returns? 
sub testUnless {
     my $v = 'Navidson';
     unless ( $v ) {
          return undef;
     }
     else {
          return $v;
     }
}
sub testIfNot {
     my $v = 'Holloway';
     if (!$v) {
          return undef;
     }
     else {
          return $v;
     }
}

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You have to understand that Perl will return the last evalution from a sub if you are not explicit. So start being explicit!

In reply to Re^3: unless versus if ( ! ) inside a subroutine by Anonymous Monk
in thread unless versus if ( ! ) inside a subroutine by Wheeler

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