use strict;
use warnings;

package Vehicle;

sub new {
     my $class = shift;
     
     # Provide some defaults
     my $self = {wheels => 4, engine => 1800, doors => 4};
     return bless $self, $class;
}

sub describe {
     my $self = shift;
     
     return <<"desc";
My engine is $self->{engine}cc.
I have $self->{wheels} wheels and $self->{doors} doors.
desc
}

package Car;

our @ISA = ('Vehicle');

sub new {
     my $class = shift;
     my $self = new Vehicle ($class);
     
     $self->{colour} = 'blue';
     return bless $self, $class;
}

sub describe {
     my $self = shift;
     my $str = $self->SUPER::describe ();
     
     return $str . <<"desc";
My colour is $self->{colour}.
desc
}

package main;

my $car = new Car;

print $car->describe ();

##</code><code>##

My engine is 1800cc.
I have 4 wheels and 4 doors.
My colour is blue.