[Tutor] OOP purpose

[Sean 'Shaleh' Perry]

On 02-Apr-2002 Cameron Stoner wrote:
> Hi all,
> 
> What is the purpose of OOP?  Why  would you use it instead of just modular 
> design?  I am having trouble finding the need to use it in my projects.
> 

OOP is just another way to think about programming.  It gives us humans a way
to think about the abstract nature of our code.

In some places it makes a whole lot of sense.  For instance GUI coding. 
Windows, buttons, titlebars, the mouse.  These are all real objects.  It
follows then to treat them as such.

Think about a file? It is a thing, you can describe it.

OOP in part is about letting the objects contain the smarts.  file.readlines().
 The file object knows how to retrieve its contents and give you a list of
them.  It does not matter if file is really a rfc822 message, a text file, or a
parsed XML object.  You think "I want the lines in the file".  In procedural
coding, you would need:

read_xml_lines()
read_database_lines()
read_rfc822_lines()

etc.  So you have separated the data from its controller.

Modular programming is part of OOP.  In a way, the modules in strict modular
programming are simple objects.