CHAPTER 54 — ArrayLists and Iterators

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

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

Chapter Topics:

• Review of fixed-length arrays.
• The ArrayList class.
• ArrayList constructors.
• The List interface.
• capacity and size.
• Methods of ArrayList
  • add()
  • clear()
  • get()
  • indexOf()
  • isEmpty()
  • remove()
  • size()
• Iterators

Several of the features described in this chapter are new to Java 25 LTS. Older versions of Java may 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.