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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

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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.


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 the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
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