#!/usr/bin/perl -w
use strict;
use Data::Dump qw(pp);
use Data::Dumper;

my %HoH = (
   flintstones => {
      lead => "fred",
      pal => "barney",
   },
   jetsons => {
      lead => "george",
      wife => "jane",
      "his boy" => "elroy",
   },
);

my $href1 = \%{$HoH{flintstones}};
my $href2 = $HoH{flintstones};
my $href3 = \%HoH;

#Fails             #yes, indeed this will fail!!
#delete($href1);
#delete($href2);

# These are both references to the sub hash of flintstones...
# sometimes the ability to omit parens in Perl is good thing
# sometime not, here not:
print pp ($href1), "\n"; #{ lead => "fred", pal => "barney" }
print pp ($href2), "\n"; #{ lead => "fred", pal => "barney" }

print "printing HOH...\n";
print pp ($href3), "\n";

#printing HOH...
#{
#  flintstones => { lead => "fred", pal => "barney" },
#  jetsons => { "his boy" => "elroy", lead => "george", wife => "jane" },
#}

foreach my $TV_show (keys %HoH)
{
   delete $HoH{$TV_show} if $HoH{$TV_show} == $href1;
}

print "printing HOH after the delete... flintstones are gone...\n";
print pp ($href3), "\n";  

#printing HOH after the delete... flintstones are gone...
#{
#  jetsons => { "his boy" => "elroy", lead => "george", wife => "jane" },
#}

##</code><code>##

change:
delete $HoH{$TV_show} if $HoH{$TV_show} == $href1;
to:
$HoH{$TV_show}={} if $HoH{$TV_show} == $href1;