Teach Yourself Borland C++ in 14 Days - portal

Getting Your Feet Wet
An object, like components described earlier, is a piece of binary software that
performs a specific programming task. (Components are objects, but not all objects
are components. I’ll get into that later.)
An object reveals to the user (the programmer using the object) only as much of itself as
needed in order to simplify its use. All internal mechanisms that the user doesn’t need to know
about are hidden from sight. All of this is rolled up in the concept of object-oriented
programming. OOP allows you to take a modular approach to programming, thus keeping
you from constantly re-inventing the wheel. C++Builder programs are OOP-oriented due to
C++Builder’s heavy use of components. Once a component is created (either one of your own
or one of the built-in C++Builder components), it can be reused in any C++Builder program.
A component can also be extended by inheritance to create a new component with additional
features. Best of all, components hide their internal details and let the programmer
concentrate on getting the most out of the component. Objects and C++ classes are discussed
in detail on Day 4, “Totally Immersed: C++ Classes and Object-Oriented Programming.”
NEW TERM
Humble Beginnings
In the beginning there was C…as far as C++ is concerned, anyway. C++ is built on the C
programming language. It has been described as “C with classes.” This foundation in C is still
very prevalent in C++ programs written today. It’s not as if C++ were written to replace C,
but rather to augment it. The rest of this chapter and much of the next chapter focus primarily
on the part of the C++ language that has its roots in C. Actually, we will be dealing with the
C language here and moving to C++ later, on Day 2, “Wading In Deeper.” You don’t have
to be concerned with which of the information presented is from C and which is from C++
because it’s all rolled up into the language we call C++.
It would be nice if presenting the C++ language could be handled sequentially. That’s not
the case, though, because all of the features we will be discussing are intertwined. Presenting
the C++ language sequentially is not possible, so I’ll take the individual puzzle pieces one at
a time and start fitting them together. Toward the end of Day 3, “Up to Your Neck in C++,”
you’ll have a fairly complete picture of the C++ language. Don’t be concerned if you do not
instantly grasp every concept presented. Some of what is required to fully understand C++
can only come with real-world experience.
Variables
Well, we have to start somewhere, so let’s take a look at variables. A variable is essentially a
name assigned to a memory location. Once you have declared a variable, you can then use
it to manipulate data in memory. That probably doesn’t make much sense to you, so let me
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