Perl builds complex datastructures based on references. Any element of a hash or array, or any scalar may contain a reference to another hash, array, or scalar (among other things). This is the basis for defining custom made datastructures. For further info, see perlref, perlreftut, perllol, and perldsc.

Perl also allows for the creation of classes and object instances based on those classes. See perlobj, perlboot, ...and there are others, but that's more than enough to get you started.

Hi perlbeginner10, apart from davido's good post your question has had the misfortune to only receive replies from our Anonymous Troll (whose posts have been deleted by now), so I thought I'd add some more detail just so you know the content/noise ratio here is usually quite high.

The decision whether to create an object to store a given data structure ultimately boils down to one question IMO: Do you want your data structure to just contain data or should it contain data-specific behaviour as well? As davido rightly pointed out, you can create a data structure of arbitrary complexity using a hash (which in turn contains references to other data structures etc.). For example, the requirement you give in your post (a string and an array in a structure) can be fulfilled like this:

my %ruler = ( title     => "King",
              fiefdoms  => ["Narnia","Gondor","Scotland"] );
[download]

(The [] brackets around the fiefdoms create an anonymous array, see perldoc perldsc for more on this.)

If this is all you want, fine, no need for an object. But if you also want the data structure to be able to exhibit some behaviour, for example

$ruler->list_fiefdoms();
[download]

You'd implement an object, e.g. (this is a bare-bone skeleton object only and you almost certainly want to do this differently):

package Ruler;

sub new {
  bless $_[1],$_[0];
}

sub list_fiefdoms {
  my $self = shift;
  print join(",",@{$self->{fiefdoms}})."\n";
}
1;
[download]

Now you could create the object with

use Ruler;
my $ruler = Ruler->new({ title     => "Tyrant",
                         fiefdoms  => ["Mordor","Giedi Prime","Texas"]
+ });
$ruler->list_fiefdoms();
[download]

And it would print the list. Note this still implements the underlying data structure as an (anonymous) hash, the only difference is that you now also have behaviour coupled with the structure which can manipulate the contained data.

Hope that helps.