How do I sort a hash of arrays by value THEN by key?

alnico has asked for the wisdom of the Perl Monks concerning the following question:

I have a hash of arrays of the following structure...

%HoA = (
    part1     => [
        'Sc',
        'John',
        'Jacob',
        'Jingle'
    ],    
   part2      => [
       'Sc',
       'Diffie',
       'Whitman'
   ]
   jpart3     => [
       'Mo',
       'Diffie',
       'Duffy'
   ]
);
[download]

I am able to sort by keys using...

sub sort_keys_ascending{
  sort keys %HoA
}
[download]

and I am able to sort by value using...

my $href = \%HoA;
sub sort_typeparm_ascending{
  sort{
        $href->{$a}[$col_id]
          cmp
        $href->{$b}[$col_id]
      }
      keys %data
}
[download]

The problem arises when I want to sort by value, then by the key itself...

sub sort_typeparm_descending{
  sort{

        $href->{$b}[ 0 ]
          cmp
        $href->{$a}[ 0 ]
           ||
        ????? KEY{$b} ?????
          cmp
        ????? KEY{$a} ?????


      }
      keys %data;
}
[download]

Do you fellas know if it's possible to do it in this format or am I completely on the wrong path? I can't find any info on how to do this. Thanks in advance, Deke

Comment on How do I sort a hash of arrays by value THEN by key? Select or Download Code

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Re: How do I sort a hash of arrays by value THEN by key? by halley (Prior) on Aug 29, 2005 at 16:17 UTC
You were very close. I adjusted indentation a little. `sort { $href->{$b}[ 1 ] cmp $href->{$a}[ 1 ] \|\| $b cmp $a } keys %data;` [download] You can chain any number of conditions with the `\|\|` operator. The special globals `$a` and `$b` get the keys (e.g., `'part2'`) to compare. -- `[ e d @ h a l l e y . c c ]`	[reply] [d/l] [select]
Re: How do I sort a hash of arrays by value THEN by key? by salva (Canon) on Aug 29, 2005 at 16:56 UTC
Do you fellas know if it's possible to do it in this format or am I completely on the wrong path? you are on the right path, but as usual TMTOWTDI... `# ascending use Sort::Key::Maker sort_ss => qw(str str); my @akeys = sort_ss { $data{$_}[0], $_ } keys %data; # descending use Sort::Key::Maker sort_rsrs => qw(-str -str); my @dkeys = sort_rsrs { $data{$_}[0], $_ } keys %data;` [download]	[reply] [d/l]