You aren't creating a sorted hash. There is no such thing as a sorted hash (well, unless you use something like Tie::IxHash).

Hashes are by nature unordered. All you are doing here is adding keys to a hash. You're adding them in the correct order, but they are stored in a (seemingly) random order.

If you want things stored in a fixed order, then use an array. Not a hash.

davorg,
There is no such thing as a sorted hash (well, unless you use something like Tie::IxHash).

Minor nit: Tie::IxHash provides a facility to maintain insertion order. Any relationship of this order to a sorted list must be done by the user.^* On the other hand, Tie::Hash::Sorted does provide a very flexible and relatively efficient way to keep your hash sorted regardless of hash modifications.

I am not advocating using tied hashes without proper consideration but rather trying to clarify a common misconception about Tie::IxHash that others seem to have.

Cheers - L~R

It does provide methods to get the keys or values, normally returned by insertion order, in asciibetical order. This does not re-order the hash.

#!/usr/local/bin/perl

use strict;
use warnings;
use Data::Dumper;
$Data::Dumper::Indent = 1;

my $hash_value = { 
  '75.34.42.17511726663' => { 
    '2005' => ['11.5', '363,842'], 
    '1995' => ['', '200,000'], 
    '2004' => ['9.2', '326,345'], 
    '2001' => ['6.7', '263,645'], 
    '1995' => ['','200,000'],
    '1997' => ['2.6', '212,118'], 
    '1998' => ['3.7', '219,980'], 
    '2002' => ['7.6', '283,665'], 
    '2006' => ['9.4', '398,148'], 
    '2000' => ['7.7', '247,015'], 
    '1996' => ['3.3', '206,680'], 
    '1999' => ['4.2', '229,281'], 
    '2003' => ['5.4', '298,857'], 
  } 
}; 

my $key = q{75.34.42.17511726663};
my @sorted_by_year;
for my $year (sort keys %{$hash_value->{$key}}) {
  push @sorted_by_year, {$year => $hash_value->{$key}{$year}};
}

print Dumper \@sorted_by_year;
[download]

Thanks wfsp.

Check out this brief article for inforomation and examples using tied hash modules that preserve ordering.

Depending on your circumstances, it may be more expedient to save your @year array and use that anywhere you need to access your data in order.

$hash_value = { 
    '75.34.42.17511726663' => {
#       '1995' => [   '',  '200,000' ],  # Duplicate key,
                                         # overwritten by next line
        '1995' => [    '',  '200,000' ], 
        '1996' => [  '3.3', '206,680' ], 
        '1997' => [  '2.6', '212,118' ], 
        '1998' => [  '3.7', '219,980' ], 
        '1999' => [  '4.2', '229,281' ], 
        '2000' => [  '7.7', '247,015' ], 
        '2001' => [  '6.7', '263,645' ], 
        '2002' => [  '7.6', '283,665' ], 
        '2003' => [  '5.4', '298,857' ],
        '2004' => [  '9.2', '326,345' ], 
        '2005' => [ '11.5', '363,842' ], 
        '2006' => [  '9.4', '398,148' ], 
    }
}; 

# To sort year from the hash 
@year= sort {$a cmp $b} keys(%{$hash_value->{'75.34.42.17511726663'}})
+;

# To do stuff with structure - year ascending order format.
my @foo_stuff;
foreach $key (@year) {
    push @foo_stuff, Foo( $hash_value->{'75.34.42.17511726663'}{$key} 
+);
}


sub Foo {
    return @$_[0];
}
[download]

In your code you have 1995 twice in your data set. Each key in a hash can only have one value, and only the last inserted value will be kept. If your data set will have multiple entries for each year, you'll need to reconsider your data structure.

Thanks TGI.