Teach Yourself C++ in 21 Days, Second Edition pdf

Teach Yourself C++ in 21 Days, Second Edition Introduction Week 1 at a Glance: Day 1 Getting Started Day 2 The Parts of a C++ Program Day 3 Variables and Constants Day 4 Expressions and Statements Day 5 Functions Day 6 Basic Classes Day 7 More Program Flow Week 1 in Review Week 2 at a Glance: Day 8 Pointers Day 9 References Day 10 Advanced Functions Day 11 Arrays Day 12 Inheritance Day 13 Polymorphism Day 14 Special Classes and Functions Week 2 in Review Week 3 at a Glance: Day 15 Advanced Inheritance Day 16 Streams Day 17 The Preprocessor Day 18 Object-Oriented Analysis and Design Day 19 Templates Day 20 Exceptions and Error Handling Day 21 Whats Next Week 3 in Review Appendixes A Operator Precedence B C++ Keywords C Binary and Hexadecimal D Answers Index Teach Yourself C++ in 21 Days, Second Edition Dedication This book is dedicated to the living memory of David Levine. Acknowledgments A second edition is a second chance to acknowledge and to thank those folks without whose support and help this book literally would have been impossible. First among them are Stacey, Robin, and Rachel Liberty. I must also thank everyone associated with my books, both at Sams and at Wrox press, for being professionals of the highest quality. The editors at Sams did a fantastic job, and I must especially acknowledge and thank Fran Hatton, Mary Ann Abramson, Greg Guntle, and Chris Denny. I have taught an online course based on this book for a couple years, and many folks there contributed to finding and eradicating bugs and errors. A very large debt is owed to these folks, and I must especially thank Greg Newman, Corrinne Thompson, and also Katherine Prouty and Jennifer Goldman. I would also like to acknowledge the folks who taught me how to program: Skip Gilbrech and David McCune, and those who taught me C++, including Steve Rogers and Stephen Zagieboylo. I want particularly to thank Mike Kraley, Ed Belove, Patrick Johnson, Mike Rothman, and Sangam Pant, all of whom taught me how to manage a project and ship a product. Others who contributed directly or indirectly to this book include: Scott Boag, David Bogartz, Gene Broadway, Drew and Al Carlson, Frank Childs, Jim Culbert, Thomas Dobbing, James Efstratiou, David Heath, Eric Helliwell, Gisele and Ed Herlihy, Mushtaq Khalique, Matt Kingman, Steve Leland, Michael Smith, Frank Tino, Donovan White, Mark Woodbury, Wayne Wylupski, and Alan Zeitchek. Programming is as much a business and creative experience as it is a technical one, and I must therefore acknowledge Tom Hottenstein, Jay Leve, David Rollert, David Shnaider, and Robert Spielvogel. Finally, I'd like to thank Mrs. Kalish, who taught my sixth-grade class how to do binary arithmetic in 1965, when neither she nor we knew why. Tell Us What You Think! As a reader, you are the most important critic and commentator of our books. We value your opinion and want to know what we're doing right, what we could do better, what areas you'd like to see us publish in, and any other words of wisdom you're willing to pass our way. You can help us make strong books that meet your needs and give you the computer guidance you require. Do you have access to CompuServe or the World Wide Web? Then check out our CompuServe forum by typing GO SAMS at any prompt. If you prefer the World Wide Web, check out our site at http://www.mcp.com NOTE: If you have a technical question about this book, call the technical support line at 317-581-3833. As the publishing manager of the group that created this book, I welcome your comments. You can fax, e-mail, or write me directly to let me know what you did or didn't like about this book as well as what we can do to make our books stronger. Here's the information: Fax: 317-581-4669 E-mail: programming_mgr@sams.mcp.com Mail: Greg Wiegand Sams Publishing 201 W. 103rd Street Indianapolis, IN 46290 Introduction This book is designed to help you teach yourself how to program with C++. In just 21 days, you'll learn about such fundamentals as managing I/O, loops and arrays, object-oriented programming, templates, and creating C++ applications all in well-structured and easy-to-follow lessons. Lessons provide sample listings complete with sample output and an analysis of the code to illustrate the topics of the day. Syntax examples are clearly marked for handy reference. To help you become more proficient, each lesson ends with a set of common questions and answers, exercises, and a quiz. You can check your progress by examining the quiz and exercise answers provided in the book's appendix. Who Should Read This Book You don't need any previous experience in programming to learn C++ with this book. This book starts you from the beginning and teaches you both the language and the concepts involved with programming C++. You'll find the numerous examples of syntax and detailed analysis of code an excellent guide as you begin your journey into this rewarding environment. Whether you are just beginning or already have some experience programming, you will find that this book's clear organization makes learning C++ fast and easy. Conventions NOTE: These boxes highlight information that can make your C++ programming more efficient and effective. WARNING: These focus your attention on problems or side effects that can occur in specific situations. These boxes provide clear definitions of essential terms. DO use the "Do/Don't" boxes to find a quick summary of a fundamental principle in a lesson. DON'T overlook the useful information offered in these boxes. This book uses various typefaces to help you distinguish C++ code from regular English. Actual C++ code is typeset in a special monospace font. Placeholders words or characters temporarily used to represent the real words or characters you would type in code are typeset in italic monospace. New or important terms are typeset in italic. In the listings in this book, each real code line is numbered. If you see an unnumbered line in a listing, you'll know that the unnumbered line is really a continuation of the preceding numbered code line (some code lines are too long for the width of the book). In this case, you should type the two lines as one; do not divide them. ● Day 1 ❍ Getting Started ■ Introduction ■ A Brief History of C++ ■ Programs ■ Solving Problems ■ Procedural, Structured, and Object-Oriented Programming ■ C++ and Object-Oriented Programming ■ How C++ Evolved ■ The ANSI Standard ■ Should I Learn C First? ■ Preparing to Program ■ Your Development Environment ■ Compiling the Source Code ■ Creating an Executable File with the Linker ■ The Development Cycle ■ Figure 1.1. ■ HELLO.CPPYour First C++ Program ■ Listing 1.1. HELLO.CPP, the Hello World program. ■ Compile Errors ■ Listing 1.2. Demonstration of ■ compiler error. ■ Summary ■ Q&A ■ Workshop ■ Quiz ■ Exercises Day 1 Getting Started Introduction Welcome to Teach Yourself C++ in 21 Days! Today you will get started on your way to becoming a proficient C++ programmer. You'll learn ● Why C++ is the emerging standard in software development. ● The steps to develop a C++ program. ● How to enter, compile, and link your first working C++ program. A Brief History of C++ Computer languages have undergone dramatic evolution since the first electronic computers were built to assist in telemetry calculations during World War II. Early on, programmers worked with the most primitive computer instructions: machine language. These instructions were represented by long strings of ones and zeroes. Soon, assemblers were invented to map machine instructions to human- readable and -manageable mnemonics, such as ADD and MOV. In time, higher-level languages evolved, such as BASIC and COBOL. These languages let people work with something approximating words and sentences, such as Let I = 100. These instructions were translated back into machine language by interpreters and compilers. An interpreter translates a program as it reads it, turning the program instructions, or code, directly into actions. A compiler translates the code into an intermediary form. This step is called compiling, and produces an object file. The compiler then invokes a linker, which turns the object file into an executable program. Because interpreters read the code as it is written and execute the code on the spot, interpreters are easy for the programmer to work with. Compilers, however, introduce the extra steps of compiling and linking the code, which is inconvenient. Compilers produce a program that is very fast each time it is run. However, the time-consuming task of translating the source code into machine language has already been accomplished. Another advantage of many compiled languages like C++ is that you can distribute the executable program to people who don't have the compiler. With an interpretive language, you must have the language to run the program. For many years, the principle goal of computer programmers was to write short pieces of code that would execute quickly. The program needed to be small, because memory was expensive, and it needed to be fast, because processing power was also expensive. As computers have become smaller, cheaper, and faster, and as the cost of memory has fallen, these priorities have changed. Today the cost of a programmer's time far outweighs the cost of most of the computers in use by businesses. Well-written, easy-to-maintain code is at a premium. Easy- to-maintain means that as business requirements change, the program can be extended and enhanced without great expense. Programs The word program is used in two ways: to describe individual instructions, or source code, created by the programmer, and to describe an entire piece of executable software. This distinction can cause enormous confusion, so we will try to distinguish between the source code on one hand, and the executable on the other. New Term: A program can be defined as either a set of written instructions created by a programmer or an executable piece of software. Source code can be turned into an executable program in two ways: Interpreters translate the source code into computer instructions, and the computer acts on those instructions immediately. Alternatively, compilers translate source code into a program, which you can run at a later time. While interpreters are easier to work with, most serious programming is done with compilers because compiled code runs much faster. C++ is a compiled language. Solving Problems The problems programmers are asked to solve have been changing. Twenty years ago, programs were created to manage large amounts of raw data. The people writing the code and the people using the program were all computer professionals. Today, computers are in use by far more people, and most know very little about how computers and programs work. Computers are tools used by people who are more interested in solving their business problems than struggling with the computer. Ironically, in order to become easier to use for this new audience, programs have become far more sophisticated. Gone are the days when users typed in cryptic commands at esoteric prompts, only to see a stream of raw data. Today's programs use sophisticated "user-friendly interfaces," involving multiple windows, menus, dialog boxes, and the myriad of metaphors with which we've all become familiar. The programs written to support this new approach are far more complex than those written just ten years ago. As programming requirements have changed, both languages and the techniques used for writing programs have evolved. While the complete history is fascinating, this book will focus on the transformation from procedural programming to object-oriented programming. Procedural, Structured, and Object-Oriented Programming Until recently, programs were thought of as a series of procedures that acted upon data. A procedure, or function, is a set of specific instructions executed one after the other. The data was quite separate from the procedures, and the trick in programming was to keep track of which functions called which other functions, and what data was changed. To make sense of this potentially confusing situation, structured programming was created. The principle idea behind structured programming is as simple as the idea of divide and conquer. A computer program can be thought of as consisting of a set of tasks. Any task that is too complex to be described simply would be broken down into a set of smaller component tasks, until the tasks were sufficiently small and self-contained enough that they were easily understood. As an example, computing the average salary of every employee of a company is a rather complex task. You can, however, break it down into these subtasks: 1. Find out what each person earns. 2. Count how many people you have. 3. Total all the salaries. 4. Divide the total by the number of people you have. Totaling the salaries can be broken down into 1. Get each employee's record. 2. Access the salary. 3. Add the salary to the running total. 4. Get the next employee's record. In turn, obtaining each employee's record can be broken down into 1. Open the file of employees. 2. Go to the correct record. 3. Read the data from disk. Structured programming remains an enormously successful approach for dealing with complex problems. By the late 1980s, however, some of the deficiencies of structured programing had became all too clear. First, it is natural to think of your data (employee records, for example) and what you can do with your data (sort, edit, and so on) as related ideas. Second, programmers found themselves constantly reinventing new solutions to old problems. This is often called "reinventing the wheel," and is the opposite of reusability. The idea behind reusability is to build components that have known properties, and then to be able to plug them into your program as you need them. This is modeled after the hardware world when an engineer needs a new transistor, she doesn't usually invent one, she goes to the big bin of transistors and finds one that works the way she needs it to, or perhaps modifies it. There was no similar option for a software engineer. [...]... DemonstrationFunction(); 17: cout . Teach Yourself C++ in 21 Days, Second Edition Introduction Week 1 at a Glance: Day 1 Getting Started Day 2 The Parts of a C++ Program Day. Yourself C++ in 21 Days, Second Edition Dedication This book is dedicated to the living memory of David Levine. Acknowledgments A second edition is a second