Professional C++, 3rd Edition

Chapter 2Working with Strings

WHAT’S IN THIS CHAPTER?

• The differences between C-style strings and C++ strings
• Details of the C++ std::string class
• What raw string literals are

WROX.COM DOWNLOADS FOR THIS CHAPTER

Please note that all the code examples for this chapter are available as a part of this chapter’s code download on the book’s website at www.wrox.com/go/proc++3e on the Download Code tab.

Every program that you write will use strings of some kind. With the old C language there is not much choice but to use a dumb null-terminated character array to represent a string. Unfortunately, doing so can cause a lot of problems, such as buffer overflows, which can result in security vulnerabilities. The C++ STL includes a safe and easy-to-use std::string class that does not have these disadvantages.

This chapter discusses strings in more detail. It starts with a discussion of the old C-style strings, explains their disadvantages, and ends with the C++ string class and raw string literals.

DYNAMIC STRINGS

Strings in languages that have supported them as first-class objects tend to have a number of attractive features, such as being able to expand to any size, or have sub-strings extracted or replaced. In other languages, such as C, strings were almost an afterthought; there was no really good “string” data type, just fixed arrays of bytes. The “string library” was nothing more than a collection of rather primitive functions without even bounds checking. C++ provides a string ...