in reply to unless versus if ( ! ) inside a subroutine

Looks like it returns the value evaluated inside the conditional. Just another reason to use explicit returns.
  • Comment on Re: unless versus if ( ! ) inside a subroutine

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Re^2: unless versus if ( ! ) inside a subroutine
by Wheeler (Acolyte) on Jan 15, 2008 at 16:37 UTC
    If we change 
    if ( ! $v ) { # ...

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    to 
    if ( $v ) { # ...

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    It still returns nothing. So it appears with 'if', it does not return the value evaluated inside the conditional. But why?
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[d/l]
[select]
      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!
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[d/l]
        The question is not on recommended practices to fix a problem but rather the perl internals regarding if and unless.
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Re^2: unless versus if ( ! ) inside a subroutine
by perlfan (Parson) on Jan 15, 2008 at 17:23 UTC
    I can respect the fact the many like "unless", but that is one of the very few aspects of Perl that I cannot stand.
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