Revised: Thu Apr 07 12:34:58 CDT 2016
This page is included in the following Books:
Table of contents
- Preface
- Preview
- Generics
- Discussion and sample code
- Run the program
- Summary
- What's next?
- Miscellaneous
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 shows you how to extract the contents of a collection into an array, and how to use a Comparator object to sort the contents of the array into reverse natural order. The module also shows you how to sortthe contents of the array into natural order without the use of a Comparator object.
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
- Listing 1 . The program named Comparator 05.
- Listing 2 . A new Vector object.
- Listing 3 . Call the fillIt method.
- Listing 4 . The fillIt method.
- Listing 5 . Iteration on a Vector.
- Listing 6 . Call the toArray method.
- Listing 7 . Display the contents of the array.
- Listing 8 . Sorting the array into natural order.
- Listing 9 . Display the sorted array data.
- Listing 10 . Sort the array with a Comparator.
- Listing 11 . The class named TheComparator.
- Listing 12 . Display the contents again.
- Listing 13 . Display the collection data again.
Preview
The primary purpose of recent modules in this series was to teach you about the interactions between the Comparator interface and the Collections Framework.
This module departs somewhat from that primary purpose and teaches you how to use a Comparator object to sort the contents of an array containing references to objects. Technically speaking, an array is not part ofthe core Collections Framework. However, it is definitely a first cousin to the Framework.