CHAPTER 54 — ArrayLists and Iterators

Programs frequently keep data in lists. Often, arrays are used for this. Arrays are a fundamental feature of most programming languages. But because lists are so useful, Java includes the ArrayList class, which works much like an array with extra methods and features.

Like an array, an ArrayList contains elements that are accessed using an integer index. However, unlike an array, the size of an ArrayList is not fixed. An ArrayList expands as needed as items are added to it.

Several of the features described in this chapter are new to Java 5.0. Older versions of Java will not work. The class ArrayList is one of the standard classes that students are expected to know for the Advanced Placement test given in the United States.