use strict;
use warnings;

my %h = ('a', ['A', 'B'], 'b', 'B','a b', 'A B');

print join('-', keys %h) . "\n\n";

print join('-', values %h) . "\n\n";

print "@{$h{'a'}}\n\n";

print "$_ => $h{$_}\n" for keys %h;
print "\n";

use Data::Dumper;
print Dumper(\%h);
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Output:

a-a b-b

ARRAY(0x1801180)-A B-B

A B

a => ARRAY(0x1801180)
a b => A B
b => B

$VAR1 = {
          'a' => [
                   'A',
                   'B'
                 ],
          'a b' => 'A B',
          'b' => 'B'
        };
[download]

Note that hashes do not retain order, so the elements may display in a different order from the order you defined them.

Personally, I prefer this format if I'm creating a hash, just makes things a lot more clear:

my %h = ( 'a' => ['A', 'B'], 'b' => 'B', 'a b' => 'A B' );