#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;

my ( $broken, $works );
my @list = qw( this that another );

for ( @list ) {
    $broken->{'this'}    = $_ eq 'this' ? 1 : 0;
    $broken->{'that'}    = $_ eq 'that' ? 1 : 0;
    $broken->{'another'} = $_ eq 'another' ? 1 : 0;
}

for ( @list ) {
    $works->{'this'}    = 1 if $_ eq 'this';
    $works->{'that'}    = 1 if $_ eq 'that';
    $works->{'another'} = 1 if $_ eq 'another';
}

print Dumper $broken, $works;

##</code><code>##

perl example.pl
$VAR1 = {
          'another' => 1,
          'that' => 0,
          'this' => 0
        };
$VAR2 = {
          'another' => 1,
          'that' => 1,
          'this' => 1
        };