In this preliminary chapter, we introduce a couple of topics we'll be using throughout the book. First, we discuss how to use classes and object-oriented programming (OOP) to aid in the development of data structures and algorithms. Using OOP techniques will make our algorithms and data structures more general and easier to modify, not to mention easier to understand.

The second part of this Introduction familiarizes the reader with techniques for performing timing tests on data structures and, most importantly, the different algorithms examined in this book. Running timing tests (also called benchmarking) is notoriously difficult to get exactly right, and in the.NET environment, it is even more complex than in other environments. We develop a Timing class that makes it easy to test the efficiency of an algorithm (or a data structure when appropriate) without obscuring the code for the algorithm or data structures.

DEVELOPING CLASSES

This section provides the reader with a quick overview of developing classes in VB. NET. The rationale for using classes and for OOP in general is not discussed here. For a more thorough discussion of OOP in VB. NET, see McMillan (2004).

One of the primary uses of OOP is to develop user-defined data types. To aid our discussion, and to illustrate some of the fundamental principles of OOP, we will develop two classes for describing one or two features of a geometric data processing system: the Point class and the Circle class.