Introduction to Objects from a C++ Perspective
This article provides an overview of the elements of C++; specifically, the 'C' portion of C++.
Note how section 2.2 describes tokens as the "minimal chunks of a program". The root goal of programming is solving problems using the 'chunks' of a programming language. Of course, the chunks must be appropriate for the type of problems to be solved. Generally, smaller chunks are applicable to many types of tasks, but involve more effort; larger chunks involve less effort, but are designed for more specific tasks.
Summary
This
chapter attempts to give you a feel for the broad issues of
object-oriented programming and C++, including why OOP is different, and
why C++ in particular is different, concepts of OOP methodologies, and
finally the kinds of issues you will encounter when moving your own
company to OOP and C++.
OOP and C++
may not be for everyone. It's important to evaluate your own needs and
decide whether C++ will optimally satisfy those needs, or if you might
be better off with another programming system (including the one you're
currently using). If you know that your needs will be very specialized
for the foreseeable future and if you have specific constraints that may
not be satisfied by C++, then you owe it to yourself to investigate the
alternatives. Even if you eventually choose C++ as your language,
you'll at least understand what the options were and have a clear vision
of why you took that direction.
You
know what a procedural program looks like: data definitions and function
calls. To find the meaning of such a program you have to work a little,
looking through the function calls and low-level concepts to create a
model in your mind. This is the reason we need intermediate
representations when designing procedural programs – by themselves,
these programs tend to be confusing because the terms of expression are
oriented more toward the computer than to the problem you're solving.
Because C++ adds many new concepts to the C language, your natural assumption may be that the main( ) in a C++ program will be far more complicated than for the equivalent C program. Here, you'll be pleasantly surprised: A well-written C++ program is generally far simpler and much easier to understand than the equivalent C program. What you'll see are the definitions of the objects that represent concepts in your problem space (rather than the issues of the computer representation) and messages sent to those objects to represent the activities in that space. One of the delights of object-oriented programming is that, with a well-designed program, it's easy to understand the code by reading it. Usually there's a lot less code, as well, because many of your problems will be solved by reusing existing library code.