Beefy Boxes and Bandwidth Generously Provided by pair Networks
Do you know where your variables are?

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

You are looking something rather like the (appropriately, given the example) factory pattern. The "method" used to create an instance is the factory.

The following is based on Moritz' sample, cleaned up and tested: :-)

use strict; use warnings; package Car; my %carByType; sub new { my ($class, %opts) = @_; return bless \%opts, $class; } sub factory { my (%opts) = @_; die "Don't know how to make a new car" if !exists $opts{name} || !exists $carByType{$opts{name}}; $carByType{$opts{name}}->new(%opts); } sub describe { my ($self) = @_; my ($make) = ref ($self) =~ m/^Car::(.*)/; print "$make $self->{name}\n"; } sub REGISTER_TYPE { my ($type, $name) = @_; $carByType{$name} = $type; } package Car::BMW; our @ISA = qw/Car/; Car::BMW->REGISTER_TYPE('Z1'); Car::BMW->REGISTER_TYPE('Z3'); package main; my $z1 = Car::factory(name => 'Z1'); $z1->describe();


True laziness is hard work

In reply to Re: Inheritance: parent class determine which child class to use? by GrandFather
in thread Inheritance: parent class determine which child class to use? by fbicknel

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others rifling through the Monastery: (3)
    As of 2018-01-22 05:35 GMT
    Find Nodes?
      Voting Booth?
      How did you see in the new year?

      Results (231 votes). Check out past polls.