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

my %hash1 = ( fred   => [ 'wilma', 'pebbles'   ],
              barney => [ 'betty', 'bamm-bamm' ], );
my %hash2 = ( homer  => [ 'marge', 'bart', 'lisa', 'maggie' ],
              romeo  => [ 'juliet' ] );
my $a     =  'fred';
my $b     =  'homer';

print "Before the assignments:\n";
print "hash1: ";
dd \%hash1;
print "hash2: ";
dd \%hash2;

my $sub = $hash1{$a} = $hash2{$b};

print "\nAfter the assignments:\n";
print "hash1: ";
dd \%hash1;
print "hash2: ";
dd \%hash2;
print "sub:   ";
dd  $sub;

push @$sub, $a;

print "\nAfter the push:\n";
print "sub:   ";
dd  $sub;