C++ Primer, Fourth Edition, provides a comprehensive introduction to the C++ language. As a primer, it provides a clear tutorial approach to the language, enhanced by numerous examples and other learning aids. Unlike most primers, it also provides a detailed description of the language, with particular emphasis on current and effective programming techniques.

Countless programmers have used previous editions of C++ Primer to learn C++. In that time C++ has matured greatly. Over the years, the focus of the language--and of C++ programmers--has grown beyond a concentration on runtime efficiency to focus on ways of making programmers more efficient. With the widespread availability of the standard library, it is possible to use and learn C++ more effectively than in the past. This revision of the C++ Primer reflects these new possiblities.

Changes to the Fourth Edition

In this edition, we have completely reorganized and rewritten the C++ Primer to highlight modern styles of C++ programming. This edition gives center stage to using the standard library while deemphasizing techniques for low-level programming. We introduce the standard library much earlier in the text and have reformulated the examples to take advantage of library facilities. We have also streamlined and reordered the presentation of language topics.

In addition to restructuring the text, we have incorporated several new elements to enhance the reader's understanding. Each chapter concludes with a Chapter Summary and glossary of Defined Terms, which recap the chapter's most important points. Readers should use these sections as a personal checklist: If you do not understand a term, restudy the corresponding part of the chapter.

We've also incorporated a number of other learning aids in the body of the text:

• Important terms are indicated in bold; important terms that we assume are already familiar to the reader are indicated in bold italics. Each term appears in the chapter's Defined Terms section.
• Throughout the book, we highlight parts of the text to call attention to important aspects of the language, warn about common pitfalls, suggest good programming practices, and provide general usage tips. We hope that these notes will help readers more quickly digest important concepts and avoid common pitfalls.
• To make it easier to follow the relationships among features and concepts, we provide extensive forward and backward cross-references.
• We have provided sidebar discussions that focus on important concepts and supply additional explanations for topics that programmers new to C++ often find most difficult.
• Learning any programming language requires writing programs. To that end, the primer provides extensive examples throughout the text. Source code for the extended examples is available on the Web at the following URL:

What hasn't changed from earlier versions is that the book remains a compre-hensive tutorial introduction to C++. Our intent is to provide a clear, complete and correct guide to the language. We teach the language by presenting a series of examples, which, in addition to explaining language features, show how to make the best use of C++. Although knowledge of C (the language on which C++ was originally based) is not assumed, we do assume the reader has programmed in a modern block-structured language.

Structure of This Book

C++ Primer provides an introduction to the International Standard on C++, covering both the language proper and the extensive library that is part of that standard. Much of the power of C++ comes from its support for programming with abstractions. Learning to program effectively in C++ requires more than learning new syntax and semantics. Our focus is on how to use the features of C++ to write programs that are safe, that can be built quickly, and yet offer performance comparable to the sorts of low-level programs often written in C.

C++ is a large language and can be daunting to new users. Modern C++ can be thought of as comprising three parts:

• The low-level language, largely inherited from C
• More advanced language features that allow us to define our own data types and to organize large-scale programs and systems
• The standard library, which uses these advanced features to provide a set of useful data structures and algorithms

Most texts present C++ in this same order: They start by covering the low-level details and then introduce the more advanced language features. They explain the standard library only after having covered the entire language. The result, all too often, is that readers get bogged down in issues of low-level programming or the complexities of writing type definitions and never really understand the power of programming in a more abstract way. Needless to say, readers also often do not learn enough to build their own abstractions.

In this edition we take a completely different tack. We start by covering the basics of the language and the library together. Doing so allows you, the reader, to write significant programs. Only after a thorough grounding in using the library-- and writing the kinds of abstract programs that the library allows--do we move on to those features of C++ that will enable you to write your own abstractions.

Parts I and II cover the basic language and library facilities. The focus of these parts is to learn how to write C++ programs and how to use the abstractions from the library. Most C++ programmers need to know essentially everything covered in this portion of the book.

In addition to teaching the basics of C++, the material in Parts I and II serves another important purpose. The library facilities are themselves abstract data types written in C++. The library can be defined using the same class-construction features that are available to any C++ programmer. Our experience in teaching C++ is that by first using well-designed abstract types, readers find it easier to understand how to build their own types.

Parts III through V focus on how we can write our own types. Part III introduces the heart of C++: its support for classes. The class mechanism provides the basis for writing our own abstractions. Classes are also the foundation for object-oriented and generic programming, which we cover in Part IV. The Primer concludes with Part V, which covers advanced features that are of most use in structuring large, complex systems.