RE: back to: improving rpg. was: what is object oriented programming

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Hans Boldt
>
> For example, defining "get" and "set" methods to access particular
> pieces of data within an "object" isn't really a part of OO. While
> it's a technique commonly used in certain OO languages,
> "encapsulation" is more an aspect of "modular programming".

Hans, this just isn't correct.  Without objects, you don't have data
members, so the issue of setters and getters just doesn't come up.  The
closest you can come is static procedure variables, which are really quite
different since a single process can't have two "objects" with different
values in the static procedure variable.

Having private data members, on the other hand, is absolutely an OO concept,
dating back as far as Simula, the first OO language, and Smalltalk, the most
OO language of all.  C++, Java and Eiffel Ada all support them.  Smalltalk
doesn't necessarily even have private methods or classes, but it still has
private variables.  And it's not an issue of compiled vs. interpreted
languages; even JavaScript and Perl support private variables (though Perl
requires a little more work).

The primary motivation of creating abstract data types (or classes) is that
global variables are a bad thing.  Thus, every OO language has the concept
of a private variable.  Not "certain" languages.  Every OO language besides
Python.

The fact that Python doesn't support private variables doesn't make them
non-OO, it makes Python different.

Joe