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Get and display the data in the container

Then the code in the next fragment uses the get method to get and display the values in each of the three elements, causing the followingtext to appear on the screen:

5 10 15

System.out.print(ref.get(0)+" "); System.out.print(ref.get(1)+" ");System.out.print(ref.get(2)+" ");

One step too far

Finally, the code in the next fragment goes one step too far and attempts to get a value from index 3, which is outside the bounds of the container.

System.out.print(ref.get(3)+" ");

This causes the get method of the container object to throw a NoSuchElementException . The program was not designed to handle this exception, so this causes the program to abort with the following text showing on thescreen:

5 10 15 java.util.NoSuchElementException at MyContainer.get(Ap154.java:49)at Worker.doIt(Ap154.java:30) at Ap154.main(Ap154.java:15)

(Note that the values of 5, 10, and 15 were displayed on the screen before the program aborted and displayed the error message.)

Back to Question 4

Answer 3

This program can produce either of the following depending on the value produced by a random boolean value generator:

  • B. Runtime Error
  • C. OK

Explanation 3

Throwing an exception

This program illustrates the use of the throw keyword to throw an exception.

(Note that the throw keyword is different from the throws keyword.)

Throw an exception if random boolean value is true

A random boolean value is obtained. If the value is true, the program throws an IllegalStateException and aborts with the following message on the screen:

java.lang.IllegalStateException at Worker.doIt(Ap153.java:29)at Ap153.main(Ap153.java:20)

If the random boolean value is false, the program runs to completion, displaying the text OK on the screen.

Instantiate a Random object

The following code fragment instantiates a new object of the Random class and stores the object's reference in a reference variable named ref .

void doIt(){ Random ref = new Random(new Date().getTime());

I'm not going to go into a lot of detail about the Random class. Suffice it to say that an object of this class provides methods that will return a pseudorandom sequence of values upon successive calls. You might think of this object as a random value generator.

Seeding the random generator

The constructor for the class accepts a long integer as the seed for the sequence.

(Two Random objects instantiated using the same seed will produce the same sequence of values.)

In this case, I obtained the time in milliseconds, relative to January 1, 1970, as a long integer, and provided that value as the seed. Thus, if you run the program two times in succession, with a time delay of at least one millisecondin between, the random sequences will be different.

Get a random boolean value

The code in the next fragment calls the nextBoolean method on the Random object to obtain a random boolean value. (Think of this as tossing a coin with true on one side and false on the other side.)

if(ref.nextBoolean()){ throw new IllegalStateException();

Throw an exception

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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