# 7.13 Ap0130: self-assessment, comparing objects, packages, import  (Page 4/9)

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B. Runtime Error

## Explanation 9

A setup

If you feel like you've been had, chances are you have been had. The purpose for Question 8 was to set you up for this question.

Division by zero for integer types

This program deals with the process of dividing by zero for int types. The code in the following fragment divides the int value 1 by the int value 0.

```void doIt(){ System.out.println(1/0);}//end doIt()```

Not the same as double divide by zero

However, unlike with type double , this process doesn't return a very large value and continue running. Rather, for type int , attempting to divide by zero will result in a runtime error of type ArithmeticException that looks something like the following under JDK 1.3:

```java.lang.ArithmeticException: / by zero at Worker.doIt(Ap149.java:20)at Ap149.main(Ap149.java:14)```

An exercise for the student

I won't attempt to explain the difference in behavior for essentially the same problem between type int and type double . As the old saying goes, I'll leave that as an exercise for the student.

C. Infinity

## Explanation 8

A double divide by zero operation

This program deals with the process of dividing by zero for floating values of type double .

The following code fragment attempts to divide the double value 1.0 by the double value 0.

```void doIt(){ System.out.println(1.0/0);}//end doIt()```

The program runs successfully, producing the output Infinity .

What is Infinity?

Suffice it to say that Infinity is a very large number.

(Any value divided by zero is a very large number.)

At this point, I'm not going to explain it further. If you are interested in learning what you can do with Infinity , see the language specifications.

B. Runtime Error

## Explanation 7

This program illustrates an IndexOutOfBounds exception.

Instantiate and populate an ArrayList object

By now, you will be familiar with the kind of container object that you get when you instantiate the ArrayList class.

The code in the following fragment instantiates such a container, having aninitial capacity of one element.

Then it adds two elements to the container. Each element is a reference to an object of the class String .

```void doIt(){ ArrayList ref = null;ref = new ArrayList(1); ref.add("ABC ");ref.add("DEF ");```

Increase capacity automatically

Because two elements were successfully added to a container having an initial capacity of only one element, the container was forced to increase its capacityautomatically.

Following execution of the code in the above fragment, String object references were stored at index locations 0 and 1 in the ArrayList object.

Get reference at index location 2

The next fragment attempts to use the get method to fetch an element from the container at index value 2.

Index values in an ArrayList object begin with zero. Therefore, since only two elements were added to the container in the earlierfragment, there is no element at index value 2.

```System.out.println( (String)ref.get(0) +(String)ref.get(1) + (String)ref.get(2));```

anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
Introduction about quantum dots in nanotechnology
what does nano mean?
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?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
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
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
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?
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 ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
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
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
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