Java Generics and Collections, 2nd Edition

Chapter 14. Lists

Lists are probably the most widely used Java collections in practice. A list is a collection that (unlike a set) can contain duplicates, and that (unlike a queue) gives the user full visibility of and control over the ordering of its elements. The corresponding Collections Framework interface is List<E>.

The List contract overrides the equals method; it states that a List can only ever be equal to another List, and then only if they contain the same elements, in the same order. The hashCode method is also overridden, as should always be the case when equals is overridden (see “Hash tables” in the section “Implementations”). The List interface documentation specifies the algorithm to be used to calculate the hashCode of a List from the hash codes of its elements.

Note

The code examples for this chapter can be found at:

https://github.com/MauriceNaftalin/JGC_2e_Book_Code/blob/main/src/main/java/org/jgcbook/chapter14

List Interface Methods

The List interface exposes methods for positional access, for searching for a given value, for generating views, and for creating ListIterators—a subtype of Iterator with additional features that take advantage of a List’s sequential nature. In addition, the methods inherited from SequencedCollection provide convenient shorter versions of common positional access calls. Finally, static factory methods are available to create unmodifiable lists of different lengths.

Positional Access Methods

void add(int index, E e)

add element ...