|
 |
[ Introduction ] [Chapter 1] [Chapter
2] [Chapter 3] [Chapter
4] [Chapter 5] [Chapter
6] [Chapter 7] [Chapter
8] [Chapter 9] [Chapter
10] [Chapter 11] [Chapter
12]
What is C++
THE ORIGIN OF C++
The C programming language was developed at AT&T for the purpose
of writing the operating system for the PDP-11 series of computers
which ultimately became the UNIX operating system. C was developed
with the primary goal of operating efficiency. Bjarne Stroustrup,
also of AT&T, developed C++ in order to add object oriented constructs
to the C language. Because object oriented technology was new at the
time and all existing implementations of object oriented languages
were very slow and inefficient, the primary goal of C++ was to maintain
the efficiency of C.
C++ can be viewed as a traditional procedural language with some additional
constructs. Beginning with C, some constructs are added for object
oriented programming and some for improved procedural syntax. A well
written C++ program will reflect elements of both object oriented
programming style and classic procedural programming. C++ is actually
an extendible language since we can define new types in such a way
that they act just like the predefined types which are part of the
standard language. C++ is designed for large scale software development.
HOW TO GET STARTED IN C++
The C programming language was originally defined by the classic text
authored by Kernigan and Ritchie, "The C Programming language",
and was the standard used by all C programmers until a few years ago.
The ANSI standard for C was finally approved in December of 1989 and
has become the official standard for programming in C. The ANSI-C
standard adds many things to the language which were not a part of
the Kernigan and Ritchie definition, and changes a few. The two definitions
are not absolutely compatible and some experienced C programmers may
not have studied the newer constructs added to the language by the
ANSI-C standard.
This tutorial will assume a thorough knowledge of the C programming
language and little time will be spent on the fundamental aspects
of the language. However, as a aid to those programmers that have
learned the dialect of C as defined by Kernigan & Ritchie, some
sections will be devoted to explaining the newer additions included
in the ANSI-C standard. As the ANSI-C standard was in development,
many of the newer constructs from C++ were included as parts of C
itself, so even though C++ is a derivation and extension of C, it
would be fair to say that ANSI-C has some of its roots in C++. An
example is prototyping which was developed for C++ and later added
to C.
The best way to learn C++ is by using it. Almost any valid C program
is also a valid C++ program and, in fact, the addition of about 12
keywords is the only reason that some C programs will not compile
and execute as a C++ program. There are a few other subtle differences,
but we will save the discussion of them until later. Since this is
true, the best way to learn C++ is to simply add to your present knowledge
and use a few new constructs as you need them for each new project.
It would be a tremendous mistake to try to use all of the new constructs
in your first C++ program. You would probably end up with an incomprehensive
mixture of code that would be more inefficient than the same program
written purely in C. It would be far better to add a few new constructs
to your toolkit occasionally, and use them as needed while you gain
experience with their use.
As an illustration of the portability of C to C++, all of the example
programs included in the Coronado Enterprises C tutorial compiled
and executed correctly when compiled as C++ programs with no changes.
Note that this was version 2.6 which was released in 1994. The updates
in the C++ compilers since then may have made this statement false
for newer versions. None of the C++ programs will compile and execute
correctly with any C compiler however, if for no other reason than
the use of the new style of C++ comments.
HOW TO USE THIS TUTORIAL
This tutorial is best used while sitting in front of your computer.
It is designed to help you gain experience with your own C++ compiler
in addition to teaching you the proper use of C++. Display an example
program on the monitor, using whatever text editor you usually use,
and read the accompanying text which will describe each new construct
introduced in the example program. After you study the program, and
understand the new constructs, compile and execute the program with
your C++ compiler.
After you successfully compile and execute the example program, introduce
a few errors into the program to see what kind of error messages are
issued. If you have done much programming, you will not be surprised
if your compiler gives you an error message that seems to have nothing
to do with the error introduced. This is because error message analysis
is a very difficult problem with any modern programming language.
The most important result of these error introduction exercises is
the experience you will gain using your compiler and understanding
its nuances. You should then attempt to extend the program using the
techniques introduced with the program to gain experience.
The way this tutorial is written, you will not find it necessary to
compile and execute every program. At the end of each example program,
listed in comments, you will find the result of execution of that
program. Some of the constructs are simple and easy for you to understand,
so you may choose to ignore compilation and execution of that example
program, depending upon the result of execution to give you the output.
Some students have used these results of execution to study several
chapters of this tutorial on an airplane by referring to a hardcopy
of the example programs.
In the text of this tutorial, keywords, variable names, and function
names will be written in bold type as an aid when you are studying
the example programs.
DIFFERENT C++ IMPLEMENTATIONS
There are primarily two standards for naming C++ files, one using
the extension CPP and the other using the extension CXX. All files
in this tutorial use the CPP extension for naming files. If your compiler
requires the CXX extension it will be up to you to rename the files.
When C++ was in its infancy, header files generally used the extension
.HPP, but there is a definite trend to use .H for all header files.
For that reason all header files in this tutorial will use that convention.
Even though we have tried to use the most generic form of all constructs,
it is possible that some constructs will not actually compile and
run with some C++ compilers. As we find new implementations of C++,
and acquire copies of them, we will compile and execute all files
in an attempt to make all example programs as universal as possible.
A committee is currently meeting to produce an ANSI-C++ standard,
but the standard is not expected to be available for general use until
1998 at the earliest. Until then we must expect a few changes to the
language. In fact, there have been many changes in the last two years
as compiler writers are trying to catch up with the language changes.
PROGRAMMING EXERCISES
There are programming exercises given at the end of each chapter to
enable you to try a few of the constructs given in the chapter. These
are for your benefit and you will benefit greatly if you attempt to
solve each programming problem. If you merely read this entire tutorial,
you will have a good working knowledge of C++, but you will only become
a C++ programmer if you write C++ programs. The programming exercises
are given as suggestions to get you started programming.
An answer for each programming exercise is given in the cppans.zip
file available for download in the same manner as the source files.
The answers are all given in compilable C++ source files named in
the format CHnn_m.CPP, where nn is the chapter number and m is the
exercise number. If more than one answer is required, an A, B, or
C, is included following the exercise number.
RECOMMENDED ADDITIONAL READING
- Margaret
Ellis & Bjarne Stroustrup. "The Annotated C++ Reference
Manual". Addison-Wesley, 1990. This is the base document
for the ANSI-C++ standard. Even though it is the definitive book
on C++, it would be difficult for a beginner to learn the language
from this book alone.
- Scott
Meyers. "Effective C++, 50 Specific Ways to Improve Your
Programs and Designs". Addison-Wesley, 1992. This book is
excellent for the advanced C++ programmer, but it is definitely
not for the beginner.
- Scott
Meyers. "More Effective C++, 35 New Ways to Improve Your
Programs and Designs". Addison-Wesley, 1996. This book is
excellent for the advanced C++ programmer, following completion
of the above reference.
- Note
that the C++ culture is in rapid change and by the time you read
this, there will be additional well written texts available as
aids to your learning the syntax and proper use of the C++ programming
language.
<< back next >>
[ Introduction ] [Chapter 1] [Chapter
2] [Chapter 3] [Chapter
4] [Chapter 5] [Chapter
6] [Chapter 7] [Chapter
8] [Chapter 9] [Chapter
10] [Chapter 11] [Chapter
12] |
|
