Hello, beloved Perl monks. My learning journey has taken me to a far and exciting land called Object-Oriented Programming (OOP). I find OOP interesting as it entails a different way of thinking and approach in programming. I am currently studying a book, Perl Objects, References & Modules (1993) by Randal L. Schwartz, and was introduced to the concepts of getters and setters. Personally, I do not feel comfortable with the idea of using setter and getter functions. I understood clearly the disadvantages of accessing class objects directly. If down the road I would need to design a class object, I would try to stay away, as possible, from using accessors. However, I am a bit frustrated because the book only illustrated how setters/getters could break the encapsulation of a class object. I made up my own example to illustrate how encapsulation could be broken into despite the success of changing the color attribute from 'red' to ‘green’. 

use strict;
use warnings;

{
    package Fruit;

    sub new {

        my $class = shift;
        my $fruit = shift;
        my $self = { name => $fruit, color => 'red' };
        
        bless $self, $class;
    };    

    sub set_color {
    
        my $self = shift;
        $self->{'color'} = shift;
    };

    sub get_color {
        my $self = shift;
        $self->{'color'};
    };    

}

    my $obj = Fruit->new('apple');
    $obj->set_color('green');
    $obj->get_color;
    
    use Data::Dumper;    
    print Dumper($obj);

[download]

I used Data::Dumper and the result is shown below:


$VAR1 = bless( {                                                      
+                                                                     
+                                      
                 'color' => 'green',                                  
+                                                                     
+                                      
                 'name' => 'apple'                                    
+                                                                     
+                                      
               }, 'Fruit' );

[download]

The chapter I read, chapter 9, did not offer definitive and non-invasive solutions on updating an object’s attribute. On the other hand, It’s also possible that I have failed to understand some key points in the chapter. My question is, are setters and getters still used these days in Perl programming? Is there a non-invasive way to update an object’s attribute? Is OOP considered a universal subject that it could be discussed without any reference to a particular programming language? Are there books that you could recommend on the subject? Thank you. :)

In reply to OOP's setter/getter method - is there a way to avoid them? by tiny_monk

Title:
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, details, 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, summary, 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.