Re: Extracting elements from array

Without the need to "manually" step over the zeroth element (i.e., process only hash refs. that have a 'name' key):

<c>
c:\@Work\Perl>perl -wMstrict -le
"use Data::Dump qw(dd);
 ;;
 my $data = [
   { val => 'action',  acc => 'Accounts',  id => 'None', },
   { name => 'PA1',  id => 'AUTOB' },
   { name => undef,  id => 'AUTOP' },
   { name =>   '0',  id => 'BOP'   },
   { name =>     0,  id => 'DFIRE' },
   { name =>    '',  id => 'HOME'  },
   { name => 'CM7',  id => 'CUMBR' },
   { name => 'BR1',  id => 'PUMBR' },
   { name => 'TY6',  id => 'ECUST' },
   ];
 ;;
 my $k = 'name';
 my $names = [
   map { exists $_->{$k} ? { $k => $_->{$k} } : () } @$data
   ];
 dd $names;
"
[
  { name => "PA1" },
  { name => undef },
  { name => 0 },
  { name => 0 },
  { name => "" },
  { name => "CM7" },
  { name => "BR1" },
  { name => "TY6" },
]
[download]

Update: Changed example code to include various false values for $k selected key.

Give a man a fish: <%-{-{-{-<

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Re^2: Extracting elements from array -- grep by Discipulus (Canon) on Jan 15, 2016 at 08:44 UTC
When i read the title i was sure grep was the solution.. when i read all solutions used map i was surprised. Using grep was trickier than i thought (but is a function i started using recently (2 years or so)) was trickier 'cause of his return value accomplished using `$_ = ..` use strict; use warnings; use Data::Dump; my $aref =[ { val => 'action', acc => 'Accounts', id => 'None', }, { name => 'PA1', id => 'AUTOB' }, { name => undef, id => 'AUTOP' }, { name => '0', id => 'BOP' }, { name => 0, id => 'DFIRE' }, { name => '', id => 'HOME' }, { name => 'CM7', id => 'CUMBR' }, { name => 'BR1', id => 'PUMBR' }, { name => 'TY6', id => 'ECUST' }, ]; dd [ grep { exists $_->{name} and $_={'name' => $_->{name}} } @$aref ] +; # OUTPUT [ { name => "PA1" }, { name => undef }, { name => 0 }, { name => 0 }, { name => "" }, { name => "CM7" }, { name => "BR1" }, { name => "TY6" }, ] [download] HtH L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l] [select]
Re^3: Extracting elements from array -- grep by AnomalousMonk (Archbishop) on Jan 15, 2016 at 16:37 UTC
`[ grep { exists $_->{name} and $_={'name' => $_->{name}} } @$aref ]` Beware that `$_={'name' => $_->{name}}` clobbers `$aref` because `$_` is an alias. (Of course, `$_` in map is also an alias, so it's possible to do oneself an injury with `map` also, but also easier to avoid. :-) Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]