Re: Extracting values from nested hashrefs

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Re^2: Extracting values from nested hashrefs by loris (Hermit) on Sep 12, 2012 at 09:35 UTC
Ah, sorry, my example was too simple. It should have been like this: `my $animals = { gnu => { humps => 0, mascot_for => 'emacs', }, dromedary => { humps => 1, mascot_for => 'perl', }, camel => { humps => 2, mascot_for => 'perl', }, };` [download] BTW, implicit traversing is OK; I just wanted to avoid some sort of loop with , say `while`. Thanks, loris	[reply] [d/l] [select]
Re^3: Extracting values from nested hashrefs by choroba (Cardinal) on Sep 12, 2012 at 09:45 UTC
You can use `map $_->{humps}, values %$animals;` [download] If your structure becomes even more complicated (e.g. different level of nesting), you should use recursion (or CPAN). لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re^3: Extracting values from nested hashrefs by Athanasius (Archbishop) on Sep 12, 2012 at 12:46 UTC
Here is an approach that should work no matter how complicated your data structure becomes (provided the data you want remains in the form `humps => d`): `#! perl use strict; use warnings; use Data::Dumper; my $animals = { gnu => { humps => 0, mascot_for => 'emacs', }, dromedary => { humps => 1, mascot_for => 'perl', }, camel => { humps => 2, mascot_for => 'perl', }, }; my $flat = Dumper($animals); print "$1\n" while $flat =~ / 'humps' \s+ => \s+ (\d+) /gx;` [download] Output: `2 0 1` [download] TMTOWTDI. Athanasius <°(((>< contra mundum	[reply] [d/l] [select]

Ah, sorry, my example was too simple. It should have been like this:

my $animals = {
               gnu => {
                       humps => 0,
                       mascot_for => 'emacs',
                      },
               dromedary => {
                             humps => 1,
                             mascot_for => 'perl',
                            },
               camel => {
                         humps => 2,
                         mascot_for => 'perl',
                        },
              };
[download]

BTW, implicit traversing is OK; I just wanted to avoid some sort of loop with , say while.

Thanks,

loris

[reply]
[d/l]
[select]

map $_->{humps}, values %$animals;
[download]

لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

[reply]
[d/l]

Here is an approach that should work no matter how complicated your data structure becomes (provided the data you want remains in the form humps => d):

#! perl
use strict;
use warnings;
use Data::Dumper;

my $animals = {
                 gnu       => {
                                 humps      =>  0,
                                 mascot_for => 'emacs',
                              },
                 dromedary => {
                                 humps      =>  1,
                                 mascot_for => 'perl',
                              },
                 camel     => {
                                 humps      =>  2,
                                 mascot_for => 'perl',
                              },
              };

my $flat = Dumper($animals);
print "$1\n" while $flat =~ / 'humps' \s+ => \s+ (\d+) /gx;
[download]

Output:

2
0
1
[download]

TMTOWTDI.

Athanasius <°(((>< contra mundum

[reply]
[d/l]
[select]