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Back to Question 9

Answer 8

False. This is an unsuccessful call to a generic method where the type of the object passed to the method isabove the upper bound on the specified generic type for the method. An attempt to compile the program results in the errorshown in Figure 11 below.

Figure 11 - Answer 8.
Q08.java:25: error: method runIt in class Foo cannot be applied to given types;aFoo.runIt(aFrame); ^required: T found: Framereason: inferred type does not conform to declared bound(s) inferred: Framebound(s): JFrame where T is a type-variable:T extends JFrame declared in method<T>runIt(T) 1 error

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Answer 7

True. This is a successful call to a generic method where the generic type for the method is above (in the inheritance hierarchy) the type of object passed as a parameter.

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Answer 6

One possible solution is shown in Listing 8 below.

Listing 8 - Answer 6.
/*File A06Foo.java ************************************************/import java.awt.*; public class A06Foo<T extends Component>{ private T param;public A06Foo(T param){this.param = param; }//end constructorpublic void runIt(){System.out.println("Object instantiated."); System.out.println(param.getClass());}//end runIt }//end A06Foo//=============================================//

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Answer 5

One possible solution is shown in Listing 9 below where T extends Component . However, causing T to extend Window, Container, Component, or Object would all be valid solutions. The upper bound for T must be at or above thetype being passed as a type parameter in the inheritance hierarchy.

Listing 9 - Answer 5.
/*File A05Foo.java ************************************************/import java.awt.*; public class A05Foo<T extends Component>{ public void runIt(){System.out.println("Object instantiated."); }//end runIt}//end A05Foo //=============================================//

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Answer 4

False. This program produces the compiler error shown in Figure 12 below. The problem is that the upper bound for the type parameter in the class named Foo(Frame) is below the type passed as a parameter (Window) in the attempt to instantiate an object of the class named Foo.

Figure 12 - Answer 4.
Q04.java:20: error: type argument Window is not within bounds of type-variable TFoo<Window>aFoo = new Foo<>(); ^where T is a type-variable: T extends Frame declared in class FooQ04.java:20: error: cannot infer type arguments for Foo<>; Foo<Window>aFoo = new Foo<>(); ^reason: no instance(s) of type variable(s) T exist so that Foo<T>conforms to Foo<Window>where T is a type-variable: T extends Frame declared in class Foo2 errors

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Answer 3

True. A type variable with multiple bounds is a subtype of all the types listed in the bound. If one of the bounds is a class, it must be specified first.

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Answer 2

False. The correct statement is:

"To declare a bounded type parameter, list the type parameter's name, followed by the extends keyword, followed by its upper bound. Note that, in this context, extends is used in a general sense to mean either "extends" (as in classes) or "implements" (as in interfaces)."

Back to Question 2

Answer 1

True. There may be times when you want to restrict the types that can be used as type arguments in a parameterized type. For example, a method that operates on numbers might only want to accept instances of Number or its subclasses. This is what bounded type parameters are for.

Back to Question 1

Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Java4240r: Review of Bounded Type Parameters
  • File: Java4240r.htm
  • Published: 10/19/13
Disclaimers:

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 compensationfor those sales nor do I know who does receive compensation. If you purchase such a book, please be aware that it is a copy of a modulethat is freely available on cnx.org and that it was made and published without my prior knowledge.

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

-end-

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
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.
Bharti
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
Daniel
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
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
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
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
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.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
Difference between extinct and extici spicies
Amanpreet Reply
While the American heart association suggests that meditation might be used in conjunction with more traditional treatments as a way to manage hypertension
Beverly Reply
Researchers demonstrated that the hippocampus functions in memory processing by creating lesions in the hippocampi of rats, which resulted in ________.
Mapo Reply
The formulation of new memories is sometimes called ________, and the process of bringing up old memories is called ________.
Mapo Reply
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