my %hash;
@hash{ 'A', 'B', 'C' } = ( 1, 2, 3 );

##</code><code>##

package InOut;

use strict;
use warnings;


my %instances;

sub new {
    my( $class, @params ) = @_;
    my $obj = bless {}, $class;
    $instances{$obj} = { params => [ @params ]};
    return $obj;
}

sub getparam {
    my ( $self, $index ) = @_;
    return $instances{$self}{params}[$index];
}

1;

package main;

use strict;
use warnings;

my $thingy = InOut->new(qw/ Bart Homer Marge Maggie Lisa / );

print $thingy->getparam( 2 ), "\n";