Chapter 3. Strings, Vectors, and Arrays

Contents

• Section 3.1 Namespace using Declarations
• Section 3.2 Library string Type
• Section 3.3 Library vector Type
• Section 3.4 Introducing Iterators
• Section 3.5 Arrays
• Section 3.6 Multidimensional Arrays
• Chapter Summary
• Defined Terms

In addition to the built-in types covered in Chapter 2, C++ defines a rich library of abstract data types. Among the most important library types are string, which supports variable-length character strings, and vector, which defines variable-size collections. Associated with string and vector are companion types known as iterators, which are used to access the characters in a string or the elements in a vector.

The string and vector types defined by the library are abstractions of the more primitive built-in array type. This chapter covers arrays and introduces the library vector and string types.

The built-in types that we covered in Chapter 2 are defined directly by the C++ language. These types represent facilities present in most computer hardware, such as numbers or characters. The standard library defines a number of additional types of a higher-level nature that computer hardware usually does not implement directly.

In this chapter, we’ll introduce two of the most important library types: string and vector. A string is a variable-length sequence of characters. A vector holds a variable-length sequence of objects of a given type. We’ll also cover the built-in array type. Like other built-in types, arrays represent facilities of the hardware. As a result, arrays are less convenient to use than the library string and vector types.

Before beginning our exploration of the library types, we’ll look at a mechanism for simplifying access to the names defined in the library.