<< Chapter < Page Chapter >> Page >
This module contains review questions and answers keyed to the module titled Java3008: Abstract Methods, Abstract Classes, and Overridden Methods.

Revised: Sat Apr 02 20:52:01 CDT 2016

This page is included in the following Books:

Table of contents

Preface

This module contains review questions and answers keyed to the module titled Java3008: Abstract Methods, Abstract Classes, and Overridden Methods .

The questions and the answers 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 code in Listing 1 produces the output shown in Figure 1 where the two numeric values shown are random but must always match.

Listing 1 . Source code for Java3008r.java.
/*File Java3008r Copyright 2013, R.G.Baldwin Rev 02/12/13*********************************************************/ import java.util.*;abstract class Java3008r{ public static void main(String[]args){ Random generator = new Random(new Date().getTime());int randomNumber = (byte)generator.nextInt(); Java3008r objRef = new Java3008rMyClass(randomNumber);System.out.println(objRef); System.out.println(objRef.getData());System.out.println(randomNumber); }//end main//Declare the signature of an abstract class. public abstract int getData();}//end class Java3008r //======================================================//class Java3008rMyClass extends Java3008r{ private int data;public Java3008rMyClass(int inData){//constructor System.out.println("Java3008r");System.out.println("Dick"); data = inData;}//end constructor public int getData(){//overridden abstract methodreturn data; }//end getData()}//end class Java3008rMyClass

.

Figure 1 . Possible output from the code in Listing 1 .
Java3008r DickBaldwin -80-80

Answer 1

Question 2

True or False? The purpose of an abstract method declaration is to establish the signature of a method that must be overridden in a (non-abstract) subclass of the class in which the abstract method is declared.

Answer 2

Question 3

True or False? When an abstract method is executed, it always exhibits default behavior defined in the class in which it is declared.

Answer 3

Question 4

True or False? An abstract method must be overridden in a subclass in order to be executed.

Answer 4

Question 5

True or False? An abstract method can be overridden once and once only and it must be overridden in the immediate subclass of the class in which it isdeclared.

Answer 5

Question 6

True or False? The existence of an abstract method in a superclass guarantees that objects instantiated from every (non-abstract) subclass of that superclass will have a concrete (executable) version of a method having that same signature.

Answer 6

Question 7

True or False? Any class can be declared abstract. The consequence of declaring a class abstract is that it is not possible to instantiate an objectof the class.

Questions & Answers

what is mutation
Janga Reply
what is a cell
Sifune Reply
how is urine form
Sifune
what is antagonism?
mahase Reply
classification of plants, gymnosperm features.
Linsy Reply
what is the features of gymnosperm
Linsy
how many types of solid did we have
Samuel Reply
what is an ionic bond
Samuel
What is Atoms
Daprince Reply
what is fallopian tube
Merolyn
what is bladder
Merolyn
what's bulbourethral gland
Eduek Reply
urine is formed in the nephron of the renal medulla in the kidney. It starts from filtration, then selective reabsorption and finally secretion
onuoha Reply
State the evolution relation and relevance between endoplasmic reticulum and cytoskeleton as it relates to cell.
Jeremiah
what is heart
Konadu Reply
how is urine formed in human
Konadu
how is urine formed in human
Rahma
what is the diference between a cavity and a canal
Pelagie Reply
what is the causative agent of malaria
Diamond
malaria is caused by an insect called mosquito.
Naomi
Malaria is cause by female anopheles mosquito
Isaac
Malaria is caused by plasmodium Female anopheles mosquitoe is d carrier
Olalekan
a canal is more needed in a root but a cavity is a bad effect
Commander
what are pathogens
Don Reply
In biology, a pathogen (Greek: πάθος pathos "suffering", "passion" and -γενής -genēs "producer of") in the oldest and broadest sense, is anything that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term pathogen came into use in the 1880s.[1][2
Zainab
A virus
Commander
Definition of respiration
Muhsin Reply
respiration is the process in which we breath in oxygen and breath out carbon dioxide
Achor
how are lungs work
Commander
where does digestion begins
Achiri Reply
in the mouth
EZEKIEL
what are the functions of follicle stimulating harmones?
Rashima Reply
stimulates the follicle to release the mature ovum into the oviduct
Davonte
what are the functions of Endocrine and pituitary gland
Chinaza
endocrine secrete hormone and regulate body process
Achor
while pituitary gland is an example of endocrine system and it's found in the Brain
Achor
what's biology?
Egbodo Reply
Biology is the study of living organisms, divided into many specialized field that cover their morphology, physiology,anatomy, behaviour,origin and distribution.
Lisah
biology is the study of life.
Alfreda
Biology is the study of how living organisms live and survive in a specific environment
Sifune
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

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