4.27 Java4140r: review

Revised: Fri Apr 08 11:14:25 CDT 2016

This page is included in the following Books:

• ITSE 2321 - Object-Oriented Programming (Java)
• Object-Oriented Programming (OOP) with Java

Table of contents

• Preface
• Questions
  • 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13
• Listings
• Answers
• Complete program listing
• Miscellaneous

Preface

This module is one in a collection of modules on Java Collections designed for teaching ITSE2321 - Object-Oriented Programming (Java) at Austin Community College in Austin, TX.

This module contains review questions and answers keyed to the module titled Java4140: The Comparator Interface, Part 6 .

Once you study that module, you should be able to answer the review questions in this module.

The questions and the answers in this module are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.

Questions

Question 1 .

True or False? The reverseOrder method of the Collections class returns a reference to an object of type String .

Answer 1

Question 2

True or False? The reverse method of the Collections class returns a reference to an object of the interface type List .

Answer 2

Question 3

True or False? A Comparator created by the reverseOrder method of the Collections class can be used to sort a list into reverse natural order .

Answer 3

Question 4

What output is produced by the program shown in Listing 1 (select one or more answers) ?

• Compiler Error
• Runtime Error
• Joe Bill Tom JOE BILL TOM
• BILL Bill JOE Joe TOM Tom
• TOM BILL JOE Tom Bill Joe
• Joe Bill Tom JOE TOM BILL
• Tom TOM Joe JOE Bill BILL
• Joe Bill Tom
• None of the above.

Answer 4

Question 5

True or False? The ArrayList class implements both the Collection interface and the List interface. Therefore, it is both a collection and a list , and adheres to the contracts and stipulations of both interfaces.

Answer 5

Question 6

True or False? The reverseOrder method returns a Comparator that imposes the reverse of the natural ordering on a collection of objects that implement the Comparable interface.

Answer 6

Question 7

True or False? The natural ordering of the elements in a collection is the ordering imposed by the objects' own compare method.

Answer 7

Question 8

True or False? All Java objects have a natural ordering .

Answer 8

Question 9

True or False? The Comparator object returned by the reverseOrder method can be used to impose a reverse natural order on any collection of objects that implement the Comparable interface.

Answer 9

Question 10

True or False? If you don't understand interfaces, they can't possibly understand Java.

Answer 10

Question 11

True or False? A SortedMap is a Map that maintains its entries in ascending order, sorted according to the values' natural ordering, or according to a Comparator provided at the time of the SortedMap creation.

Answer 11

Question 12

True or False? An object of type Map is an object that maps keys to values. Such an object can contain duplicate keys but cannot containduplicate values

Answer 12

Question 13

True or False? An object of type Deque allows elements to be inserted, retrieved, and removed at both ends.