Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

comment on

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

Not all objects need setter methods. Not all values associated with an object with setters needs its own setter. The getter/setter pair is for things that are both to be accessed by other code outside your object and mutable (that is, updatable) outside the object or from elsewhere in the object.

If you want an immutable value within your object, you don't have to provide a setter. This won't enforce encapsulation by itself, but it makes it apparent that there's an intent that the value not be updated. Actual enforcement of data hiding is a separate topic.

If some piece of data should remain entirely private to your object or to the class, then there's no need to create a getter for it, either.

As for encapsulation within the object, yes it's important that if you have a getter or setter that it retrieves or updates the data in the data structure itself. However, there is some convincing argument on either side of the issue of whether one value's setter and getter should ever access another value within the object directly even within the same object. Some people say direct access to another value in the same object is fine. Others recommend that any part of the object that isn't value B's getter or setter use those methods to access value B.

Maybe you have a fruit that changes color as it ripens, but it's never going to change what kind of fruit it is.:

use strict; use warnings; package Fruit; sub new { my $class = shift; my $self = { name => shift, color => shift }; bless $self, $class; }; sub get_color { return $_[0]->{ 'color' }; } sub set_color { $_[0]->{ 'color' } = pop; } sub get_name { return $_[0]->{ 'name' }; } package main; my $obj = Fruit->new( 'apple', 'red' ); my $obj2 = Fruit->new( 'banana', 'green' ); $obj2->set_color( 'yellow' ); use Data::Dumper; print Dumper( $obj, $obj2 ); for my $fruit ( $obj, $obj2 ) { printf "The %s is %s\n", $fruit->get_name, $fruit->get_color; }

In reply to Re^5: OOP's setter/getter method - is there a way to avoid them? by mr_mischief
in thread 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":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others about the Monastery: (6)
As of 2023-01-28 17:49 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?