Iterate through Hash of Hashes

Here's how you would iterate through multidimensional hashes in Perl:

Create a hash first:

#!/usr/bin/perl
use warnings;
use strict;

my %HoH = (
    flintstones => {
        husband   => "fred",
        wife   => "wilma",
        pal   => "barney",
    },
    jetsons => {
        husband   => "george",
        wife      => "jane",
        "his boy" => "elroy",  # Key quotes needed.
    },
    simpsons => {
        husband   => "homer",
        wife      => "marge",
        kid       => "bart",
    },
);

Then iterate through it:

foreach my $family (keys %HoH) {
    while (my ($key, $value) = each %{ $HoH{$family} } ) {
        print "$key = $value \n";
    }
}

Other operations

Insert another set of values:

$HoH{ mash } = {
    captain  => "pierce",
    major    => "burns",
    corporal => "radar",
};

Access particular value:

print $HoH{flintstones}{wife}; # will output "wilma"

Set value of a particular key:

$HoH{$flintstones}->{wife} = "jane"; #give Fred a new wife