RE: OO-RPG

[Jim Langston <jlangston@xxxxxxxxxxx>]

OO programming is... different... than our normal straight down programming.

I oft times think it would of been a lot faster for me to learn C++ if I didn't 
know C to begin with.  It takes a different thought process, for me anyway.

In RPG and other conventional languages (C, Basic, etc..) our program starts 
from the first line and ends at the bottom controlled by our program logic (I 
won't even bring GOTOs into this mix), and it is fairly simple to follow 
program flow and logic.

OOs, on the other hand, can get extremely convoluted.  The main program cycle 
still starts from the top and goes to the bottom, but a lot of times the "main" 
is extremely short and there is no telling how anything is getting done, until 
you start poking around behind the scenes.

In RPG when we do an assignment such as:
Eval   A = B
We can say what that does.  It assigns the variable A to the value stored in B. 
 Simple.

In OO when we do an assignment something like:
  MyClass* A = new(MyClass);
(or)
  MyClass A;

We really don't know what that does until we look and see what MyClass is.  We 
do know that in the end our Variable A will store a pointer to a new object of 
type MyClass.  When MyClass was creating code stored in the "constructor" is 
run.  And this constructor can do anything under the sun, including creating 
it's own objects, setting pointers, setting up arrays, initializing a TCP/IP 
stack, etc...

OOs is different.  It takes a different methodology for programming in and for 
interpreting OO programs.  But when you start to finally "get" it all you can 
think is "Wow!" and "I've always wanted to be able to do that!".

Regards,

Jim Langston

-----Original Message-----
From: Bartell, Aaron L. (TC) [mailto:ALBartell@taylorcorp.com]

I guess I was asking the same questions as you are and I didn't believe
anybody that OO was good until I started using Java.  So I am unsure if I
could convince you of the benefits of OO.  I would recommend reading a book
called Thinking In Java to get a jump start.

Aaron Bartell