Modern C++ can be thought of as comprising three parts:

• The low-level language, much of which is inherited from C

• More advanced language features that allow us to define our own types and to organize large-scale programs and systems

• The standard library, which uses these advanced features to provide useful data structures and algorithms

Most texts present C++ in the order in which it evolved. They teach the C subset of C++ first, and present the more abstract features of C++ as advanced topics at the end of the book. There are two problems with this approach: Readers can get bogged down in the details inherent in low-level programming and give up in frustration. Those who do press on learn bad habits that they must unlearn later.

We take the opposite approach: Right from the start, we use the features that let programmers ignore the details inherent in low-level programming. For example, we introduce and use the library string and vector types along with the built-in arithmetic and array types. Programs that use these library types are easier to write, easier to understand, and much less error-prone.

Too often, the library is taught as an “advanced” topic. Instead of using the library, many books use low-level programming techniques based on pointers to character arrays and dynamic memory management. Getting programs that use these low-level techniques to work correctly is much harder than writing the corresponding C++ code using the library.

Throughout C++ Primer, we emphasize good style: We want to help you, the reader, develop good habits immediately and avoid needing to unlearn bad habits as you gain more sophisticated knowledge. We highlight particularly tricky matters and warn about common misconceptions and pitfalls.

We also explain the rationale behind the rules—explaining the why not just the what. We believe that by understanding why things work as they do, readers can more quickly cement their grasp of the language.

Although you do not need to know C in order to understand this book, we assume you know enough about programming to write, compile, and run a program in at least one modern block-structured language. In particular, we assume you have used variables, written and called functions, and used a compiler.