This
chapter will introduce enough C++ syntax and program construction concepts to
allow you to write and run some simple object-oriented programs. In the
subsequent chapter we will cover the basic syntax of C and C++ in detail.
By
seeing this chapter first, you’ll get the basic flavor of what it is like
to program with objects in C++, and you’ll also discover some of the
reasons for the enthusiasm surrounding this language. This should be enough to
carry you through Chapter 3, which can be a bit exhausting since it contains
most of the details of the C language.
The
user-defined data type,
or
class,
is what distinguishes C++ from traditional procedural languages. A class is a
new data type that you or someone else creates to solve a particular kind of
problem. Once a class is created, anyone can use it without knowing the
specifics of how it works, or even how classes are built. This chapter treats
classes as if they are just another built-in data type available for use in
programs.
Classes
that someone else has created are typically packaged into a library.
This chapter uses several of the class libraries that come with all C++
implementations. An especially important standard library is iostreams, which
(among other things) allows you to read from files and the keyboard, and to
write to files and the display. You’ll also see the very handy
string
class,
and the
vector
container
from the Standard Template Library (STL). By the end of the chapter,
you’ll see how easy it is to utilize a pre-defined library of classes.
In
order to create your first program you must understand the tools used to build
applications.