Re: Point me in the right direction with OO inheritance and static variables

hi Amblikai,
If what choroba and tobyink gave are too strong a drink to take all at once, you can check this soft milk

use warnings;
use strict;

package Animal;

sub new {
    my $class = shift;
    my $self  = {
        'name' => shift || 'Ologbo',
        'tail' => shift || 'Yes',
    };
    return bless $self, $class;
}

package Cat;
use base 'Animal';

sub nameMe {
    my $self = shift;
    return $self->{'name'};
}

package main;

my $cat = Animal->new;
print $cat->{'name'}, $/; # Ologbo

my $cat2 = Cat->new('Blackky');
print $cat2->nameMe       # Blackky
[download]

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

Comment on Re: Point me in the right direction with OO inheritance and static variables Download Code

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Re^2: Point me in the right direction with OO inheritance and static variables by McA (Priest) on Sep 02, 2014 at 14:38 UTC
Hi 2teez, I'm not really happy with your suggestion for a newcomer. Why? 1) Choroba presented a simple constructor (as strong as pure water to stay with your metaphor) where you can can overwrite the default values of `name` and `tail` independently in a way most people would expect working with constructors in Perl. The positional parameters to `new` you present is not very common IMHO. So, I think Corion's constructor is really simple enough. 2) In package `main` you then do a `print $cat->{'name'}, $/;` [download] which means you circumvent encapsulation (yes, I know, for debugging purposes). You show that to a newcommer to whom should be taught the "right" thing. 3) The point above IMHO comes only from the fact that you define the method `nameMe` in the child class. Why haven't you defined it in the base class? Then you wouldn't have to break encapsulation in your example and you would have shown inheritance in a nice mini example. Be sure, I wouldn't have written this comment when Amblikai wouldn't have been so "excited" about your example. Please consider my comment as a hopefully constructive criticism. And yes, Tobyink's answer is a hard drink to newcomers, but worth studying. Best regards McA	[reply] [d/l] [select]
Re^2: Point me in the right direction with OO inheritance and static variables by Amblikai (Scribe) on Sep 02, 2014 at 11:44 UTC
Thanks, the way you are doing defaults is a bit simpler and might be sufficient for my program. I'm learning this stuff though so anything is good to see! Cheers!	[reply]