package C1;

sub new {
    my $class   = shift;
    my $self    = {};
    return bless $self, $class;
}

sub printGoodBye{ print "Goodbye @_ "; printWorld(); }
sub printWorld{ print "World\n @_"; }

1;
END {}
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package C2;
use base ("C1");

sub new {
    my $class   = shift;
    my $self    = {};

    return bless $self, $class;
}

sub printHi{ print "Hi\n"; }

1;
END {}
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#!/usr/bin/perl

use C2;

$bob = C2->new();
$bob->printGoodBye();

exit 0;
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Let me know if I'm wrong, but this sure looks like it's inheriting something w/o $self being passed to me.

But it *is* passed, actually $bob is passed as the first element of @_ which is seen in the output

Goodbye C2=HASH(0x177f054) World
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So you would normally shift off the first element to a lexical variable often called $self to use the subroutine as a method in OO-style

sub printGoodBye {
  my $self = shift;
  print "Goodbye ";
  $self->printWorld();
}
sub printWorld{ 
    my $self = shift;
    print "World\n ";
}
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So inheritance is really in play here.
I am also a newbie when it comes to perl-OO, so I watch this thread with keen interest.(++)

I think you have shown me what I'm doing wrong here. Inside of your printGoodBye method, you call printWorld() w/ $self as the invocant whereas I had always been calling that method without any invocant at all. Heh, java rears it's ugly head :)

This must be what robartes meant when he wrote: "...it is a good idea that even your private methods use the class' public accessor methods to get at private instance attributes."

Excellent, excellent.

Now, I'm still not too sure about a subroutine being required to recieve a copy of the invocant in order for it to be classified as a method and thus inheritable. You are right that printGoodBye() recieves the invocant, but printWorld() does not (or else there would be a HASH=... after "World" in the output). However, printWorld is still inherited from C1 by C2.

So, chances are, I'm thinking about this in java-world and being stupid again. But, my original question has been answered, so thanks, guha.



Mark

Unless you pass $class instead.