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

use constant FOO => 'the FOO key';

my %h1 = ( +FOO  => "the value" , FOO_const => FOO);
my %h2 = ( FOO , "the value",  FOO => "other value");  # comma
my @a  = ( +FOO, FOO);

print(Dumper(\%h1, \%h2, \@a), $h2{+FOO}, "\n");

##</code><code>##

$VAR1 = {
          'FOO' => 'the value',
          'FOO_const' => 'the FOO key'
        };
$VAR2 = {
          'FOO' => 'other value',
          'the FOO key' => 'the value'
        };
$VAR3 = [
          'the FOO key',
          'the FOO key'
        ];
the value