How to sort an array of hashes based on one of the values in the hash?

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

I have the following code:

my @AoH = (
    {
        Lead => "fred",
        Wife => "wilma",
        Son => "bambam",
    },
    {
        Lead     => "george",
        Wife     => "jane",
        Son      => "elroy",
    },
    {
        Lead     => "homer",
        Wife     => "marge",
        Son      => "bart",
    });

for my $i ( 0 .. $#AoH )
{
    print "$i is { ";
    for my $role ( keys %{ $AoH[$i] } )
    {
        print "$role=$AoH[$i]{$role} ";
    }
    print "}\n";
}
[download]

This gives the following output:

0 is { Son=bambam Lead=fred Wife=wilma}
1 is { Son=elroy Lead=george Wife=jane }
2 is { Son=bart Lead=homer Wife=marge }
[download]

I want to create another array of hashes that sorts the original array of hashes based on the values of the "Son" field, so the output becomes:


Original AoH:
0 is { Son=bambam Lead=fred Wife=wilma}
1 is { Son=elroy Lead=george Wife=jane }
2 is { Son=bart Lead=homer Wife=marge }

New AoH:
0 is { Son=bambam Lead=fred Wife=wilma}
1 is { Son=bart Lead=homer Wife=marge }
2 is { Son=elroy Lead=george Wife=jane }
[download]

How do I do this?

Comment on How to sort an array of hashes based on one of the values in the hash? Select or Download Code

Replies are listed 'Best First'.
Re: How to sort an array of hashes based on one of the values in the hash? by tangent (Parson) on Mar 08, 2013 at 15:29 UTC
With real world data I would use: `@AoH = sort { lc($a->{'Son'}) cmp lc($b->{'Son'}) } @AoH;` [download]	[reply] [d/l]
Re: How to sort an array of hashes based on one of the values in the hash? by blue_cowdawg (Monsignor) on Mar 08, 2013 at 15:25 UTC
`############################################## # Wrong! (thanks tobylink) #@AoH = sort { $a->{Son} <=> $b->{Son} } @AoH; # Correct. @AoH = sort { $a->{Son} cmp $b->{Son} } @AoH;` [download] Peter L. Berghold -- Unix Professional Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg	[reply] [d/l]
Re^2: How to sort an array of hashes based on one of the values in the hash? by tobyink (Canon) on Mar 08, 2013 at 15:49 UTC
Yes, but you want `cmp` not `<=>`. `cmp` is for ASCIIbetical sorting; `<=>` is for numeric sorting. (And Unicode::Collate is for proper, decent alphabetical sorting.) `package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name`	[reply] [d/l] [select]
Re^3: How to sort an array of hashes based on one of the values in the hash? by blue_cowdawg (Monsignor) on Mar 08, 2013 at 16:34 UTC
Yes, but you want cmp not <=>. Dammit! My fingertips did it again! I thought one thing and typed another! Peter L. Berghold -- Unix Professional Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg	[reply]