4.13 Java4070r: review

Revised: Wed Apr 06 21:57:52 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
• Listings
• Answers
• Complete program listings
• 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 Java4070: The Comparable Interface, Part 1 .

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 fact that the location of each element can be controlled in a List is what causes a List to be an unordered collection.

Answer 1

Question 2

True or False? It is not necessary for objects to implement the Comparable interface to make them eligible for inclusion in a List .

Answer 2

Question 3

True or False? It is not necessary for objects to implement the Comparable interface to make them eligible for inclusion in a SortedSet .

Answer 3

Question 4

What output is produced by the program shown in Listing 1 ?

• Compiler Error
• 44321
• 4321
• 1234
• 12344

Answer 4

Question 5

True or False? The Collection interface declares the following overloaded versions of the add method. (See the Java documentation.)

• add(Object o)
• add(int index, Object element)

Answer 5

Question 6

True or False? A List object is a more-specialized collection than a Collection object.

Answer 6

Question 7

True or False? The version of the add method that requires two parameters cannot be called on a reference to an ArrayList object when that object is treated as the generic type Collection . (See the Java documentation.)

Answer 7

Question 8

What output is produced by the program shown in Listing 2 ?

• Compiler Error
• 44321
• 4321
• 1234
• 12344
• 443521

Answer 8

Question 9

True or False? A List is an ordered collection because the user has control over the location of each element in the collection relative to the otherelements in the collection.

Answer 9

Question 10

What output is produced by the program shown in Listing 3 ?

• Compiler Error
• Runtime Error
• 44321
• 4321
• 1234
• 12344

Answer 10

Question 11

True or False? Because a List makes no attempt to eliminate duplicate elements, or to sort the elements on the basis of their values, there is norequirement to compare objects when placing them in a List . Therefore, objects whose references are stored in a List are not required to implement the Comparable interface (but they may implement the Comparable interface without causing any harm) .

Answer 11

Question 12

True or False? Because a SortedSet does eliminate duplicates and does sort the elements on the basis of their values, there is a requirement to compare each new element with the existing elements in a SortedSet whenever a new element is added to the collection. Therefore, objects whosereferences are stored in a SortedSet are required to implement the Comparable interface.