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Figure 6 - Question 11.

Answer 11

Question 12

Design and write a class named A12Box which, when used in conjunction with the code shown in Listing 7 , will compile and run successfully producing the output shown in Figure 7 .

Listing 7 - Question 12.
/*File Q12.java ************************************************/public class Q12{public static void main(String[] args){A12Box<String,Integer>boxA = new A12Box<>("abcde",new Integer(500)); System.out.println(boxA.get1());System.out.println(boxA.get2());A12Box<Integer,String>boxB = new A12Box<>(new Integer(900),"fghijkl"); System.out.println(boxB.get1());System.out.println(boxB.get2()); }//end main}//end class Q12 //=============================================//
Figure 7 - Question 12.
abcde 500900 fghijkl

Answer 12

Question 13

Given: When mixing legacy code with generic code, you may encounter messages similar to those shown in Figure 8 .

Figure 8 - Question 13.
Note: Example.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.

True or False: In such cases, the term "unchecked" means that the compiler does not have enough type information to perform all type checks necessary to ensure type safety.

Answer 13



What is the meaning of the following two images?

These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.

Spacer image of a rabbit and a penguin.

This image was also inserted for the purpose of inserting space between the questions and the answers.

Spacer image of a penguin and some houses.


Answer 13


Back to Question 13

Answer 12

One possible solution is provided in Listing 8 below.

Listing 8 - Answer 12.
/*File A12Box.java ************************************************/public class A12Box<T1,T2>{ private T1 t1;private T2 t2; public A12Box(T1 t1,T2 t2){this.t1 = t1; this.t2 = t2;}//end constructorpublic T1 get1(){ return t1;}//end get1public T2 get2(){ return t2;}//end get2 }//end A12Box//=============================================//

Back to Question 12

Answer 11

One possible solution is provided in Listing 9 below.

Listing 9 - Answer 11.
/*File A11Box.java ************************************************/public class A11Box<T>{ private T t;public A11Box(T t){ this.t = t;}//end constructorpublic T get(){ return t;}//end get }//end A11Box//=============================================//

Back to Question 11

Answer 10


Back to Question 10

Answer 9

False. This program produces the error message shown in Figure 9 below.

Figure 9 - Answer 9.
Q09.java:8: error: illegal start of type Box<>box = new Box<Integer>(); ^1 error

Back to Question 9

Answer 8

One possible solution is shown in Listing 10 below.

Listing 10 - Answer 8.
/*File A08Box.java ************************************************/public class A08Box<T>{ private T t;public void set(T t){ this.t = t;}//end setpublic T get(){ return t;}//end get }//end A08Box//=============================================//

Back to Question 8

Answer 7

False. This program produces the compiler errors shown in Figure 10 below.

Figure 10 - Answer 7.
Q07.java:8: error: type Box does not take parameters Box<Integer>box = new Box<Integer>(); ^Q07.java:8: error: type Box does not take parameters Box<Integer>box = new Box<Integer>(); ^2 errors

Back to Question 7

Answer 6


Back to Question 6

Answer 5


Back to Question 5

Answer 4


Back to Question 4

Answer 3

False. The correct statement is:

"Type parameters provide a way for you to re-use the same code with different inputs. The inputs to type parameters are types ."

Back to Question 3

Answer 2


Back to Question 2

Answer 1

False. The correct statement is

"Generics add stability to your code by making more of your bugs detectable at compile time ."

Back to Question 1


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Java4220r: Review of Generic Types
  • File: Java4220r.htm
  • Published: 09/02/13

Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, youshould be aware that some of the HTML elements in this module may not translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.


Questions & Answers

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
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
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.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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