<< Chapter < Page Chapter >> Page >
This module explains why the elements stored in a TreeSet collection must be references to objects instantiated from a class that implements the Comparable interface. The module also briefly discusses an alternative approach using the Comparator interface. The module shows you how to implement the Comparable interface for a new class definition, explains the "natural ordering of the elements" for a class, and discusses the "consistent with equals" requirement. Finally, the module shows you how to define a new class whose objects are eligible for inclusion in a TreeSet collection.

Revised: Wed Apr 06 22:21:03 CDT 2016

This page is included in the following Books:

Table of contents

Preface

This module is one of a series of modules designed to teach you about Object-Oriented Programming (OOP) in general and the Java Collectionsframework in particular.

This module explains why the elements stored in a TreeSet collection must be references to objects instantiated from a class that implements the Comparable interface. The module also briefly discusses an alternative approach using the Comparator interface.

The module shows you how to implement the Comparable interface for a new class definition, explains the "natural ordering of the elements" for a class, and discusses the "consistent with equals" requirement. Finally,the module shows you how to define a new class whose objects are eligible for inclusion in a TreeSet collection.

In addition to studying these modules, I strongly recommend that you study the Collections Trail in Oracle's Java Tutorials . The modules in this collection are intended to supplement and not to replace those tutorials.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the listings while you are reading about them.

Listings

Preview

In this module, I will teach you why the elements stored in a TreeSet collection must be references to objects instantiated from a class thatimplements the Comparable interface. ( In a subsequent module, I will teach you about an alternative approach that makes use of the Comparator interface.)

I will provide an example of implementing the Comparable interface for a new class definition, and will teach you about the natural ordering of the elements for a class.

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Object-oriented programming (oop) with java' conversation and receive update notifications?

Ask