Exploring Hash of Hash

[facemann]

I am curious.
I have created a Hash of Hash as follows:
$HoH{$last_name}{$first_name}{$birth_day}{$phone_num} = "$id_num";
I often know the values of ($last_name, $first_name) and would like to find the
$birth_day value for this individual.
Is there an elegant way to do this?

Naturally:
print "$HoH{$last_name}{$first_name}"; #only prints a memory address.

My solution was to use keys:
for my $birthday(keys %{$HoH{$last_name}{$first_name} } ) {
my $key_id = $HoH{$last_name}{$first_name};
print "Birthday = $birthday\n";
}

Is there a simpler soulution? Thanks for any suggestions as I spent considerable time fighting this!

 

[AHinMaine]

Whenever you find yourself treating keys as values, realize that it's a BadIdea(tm).

For this case, I would do:

my %foo = (
    $id => {
        last  => 'harrison',
        first => 'andy',
        phone => 'myphone',
        dob   => 'bday'
    }
);

Then you can do things like:

print $foo{$id}{last};

You can also easily iterate all your id's and grab individual values or whatever you like.

--
Andy

http://www.nachoz.com

"Historically speaking, the presence of wheels in Unix has never precluded their reinvention."
Larry Wall

 

[facemann]

Thanks for the reply naChoZ.
Your %foo hash is a valid solution. However, I needed the multilevel hash because I was checking each person for duplicates. I am parsing a file for a database.
But, you have hit the nail on the head with your comment "treating keys as values". That's exactly what I was doing and why I was so frustrated. Ah, why does the learning curve have to be UPHILL? ;-)
Thanks again.

 

[AHinMaine]

Simple enough. Just search the monastary for hash duplicates or something like that and you'll see plenty of responses.

--
Andy
"Historically speaking, the presence of wheels in Unix has never precluded their reinvention." -- Larry Wall