use Perl

• Re: (Score:1)

  by Aristotle (5147) <pagaltzis@gmx.de> on 2006.04.09 17:54 (#47062) Homepage Journal

  foreach my $i ( map { $_ * 2 } 0 .. $#_ / 2 ) {
      ...
  }

  ?

  Reply to This

  • Re: (Score:1)

    by Sidhekin (6361)

    foreach my $i ( grep { ~$_ & 1 } 0 .. $#_ ) {
        ...
    }

    ?

    --
    perl -e 'print "Just another Perl ${\(trickster and hacker)},";'
    The Sidhekin proves that Sidhe did it!
    • Re: (Score:1)

      by Aristotle (5147)

      Same thing as Ovid’s, only painted green. Both his and yours make two to throw one away, whereas the approach I took does not.
      • Re: (Score:1)

        by Sidhekin (6361)

        for ( my $i = 0 ; $i <= $#_ ; $i += 2 ) {
            ...
        }

        ?

        --
        perl -e 'print "Just another Perl ${\(trickster and hacker)},";'
        The Sidhekin proves that Sidhe did it!
        • Readability (Score:1)

          by ChrisDolan (2855)

          This one scores highest on readability. I assert that the other ones are too hard to understand and, thus, more likely to be buggy (i.e. off-by-one errors).
          
          I think the best version is simply:
          
                  for ( my $i = 0; $i @_; $i += 2 ) { ...
                  }
          
          It clearly selects even numbers and ends before just before the end of the array. The "@_" is more readable than "$#_", I say.
          
          • Re:Readability (Score:1)

            by Aristotle (5147)

            foreach my $i ( 0 .. $#_ / 2 ) {
                my $j = $i * 2;
                ...
            }

            ?

            The most readable is actually if you can afford to destroy the array, which in Ovid’s case is probably true (because it is usually true for @_):

            while( @_ ) {
                ...
                splice @_, 0, 2;
            }