Chapter2.Collections

Chapter 2. Collections

• Collection Interfaces

• Concrete Collections

• The Collections Framework

• Algorithms

• Legacy Collections

Object-oriented programming (OOP) encapsulates data inside classes, but this doesn't make the way in which you organize the data inside the classes any less important than in traditional programming languages. Of course, how you choose to structure the data depends on the problem you are trying to solve. Does your class need a way to easily search through thousands (or even millions) of items quickly? Does it need an ordered sequence of elements and the ability to rapidly insert and remove elements in the middle of the sequence? Does it need an array-like structure with random-access ability that can grow at run time? The way you structure your data inside your classes can make a big difference when it comes to implementing methods in a natural style, as well as for performance.

This chapter shows how Java technology can help you accomplish the traditional data structuring needed for serious programming. In college computer science programs, a course called Data Structures usually takes a semester to complete, so there are many, many books devoted to this important topic. Exhaustively covering all the data structures that may be useful is not our goal in this chapter; instead, we cover the fundamental ones that the standard Java library supplies. We hope that, after you finish this chapter, you will find it easy to translate any of your data structures to the Java programming language.