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Answers

Answer 25

False. Listing 1 causes the following text to appear on the screen:

1234

Back to Question 25

Answer 24

True.

Back to Question 24

Answer 23

True.

Back to Question 23

Answer 22

True.

Back to Question 22

Answer 21

False. The concept of in order means different things for different Collection objects. For a collection instantiated from the TreeSet class, for example, in order means in ascending order. However, that may not be the case for a differentobject instantiated from a class that implements the Collection interface.

Back to Question 21

Answer 20

True.

Back to Question 20

Answer 19

True.

Back to Question 19

Answer 18

False. In Listing 1 , when the fillIt method returns, the TreeSet object contains four (not five) elements with no duplicates. Each element is a reference to an object of type Integer . Those references are maintained in such a way as to make them accessible in ascending order, based on the int values encapsulated in each of the Integer objects.

Back to Question 18

Answer 17

False. In Listing 1 , when the fillIt method returns, the TreeSet object contains four (not five) elements with no duplicates.

Back to Question 17

Answer 16

True. For example, the behavior of the add method for an object of the TreeSet class will probably be different from the behavior ofthe add method for an object of some other class that implements the Collection interface.

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Answer 15

False. The fillIt method receives the reference as type Collection . This method doesn't know, and doesn't care, what the actual type of the object is. All it cares about is that the object is a Collection object. (Otherwise, the object's reference couldn't be passed in as a parameter. A type mismatch would occur.) A TreeSet object is a Collection because the TreeSet class implements the Collection interface. A Button object is not a Collection because the Button class does not implement the Collection interface.

Back to Question 15

Answer 14

True.

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Answer 13

True.

Back to Question 13

Answer 12

True.

Back to Question 12

Answer 11

False. The TreeSet class implements the SortedSet interface. This guarantees that the contents of a TreeSet object will be in ascending element order, regardless of the order in which the elements areadded.

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Answer 10

False. An object of the TreeSet class also is a Set . One of the characteristics of a Java Set (an object that implements the Set interface) is that it can contain no duplicate elements. Therefore, a TreeSet object can contain no duplicate elements.

Back to Question 10

Answer 9

True.

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Answer 8

True.

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Answer 7

False. a TreeSet object is a Collection . Therefore, a reference to a TreeSet object can be stored in a reference variable of type Collection , and can be treated as the generic type Collection .

Back to Question 7

Answer 6

True.

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Answer 5

False. Listing 1 instantiates an object of the TreeSet class and stores the object's reference in a reference variable of type Collection named ref .

Back to Question 5

Answer 4

True.

Back to Question 4

Answer 3

False. Some collections are ordered and others are not.

Back to Question 3

Answer 2

True.

Back to Question 2

Answer 1

False. The framework is designed to encourage you to reuse rather than to reinvent collections and maps.

Back to Question 1

Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Java4010r Review: Java4010: Getting Started with Java Collections
  • File: Java4010r.htm
  • Published: 11/24/13
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 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.

-end-

Questions & Answers

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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
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
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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