# 7.4 Ap0040: self-assessment, logical operations, numeric casting,  (Page 7/8)

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Not the same as rounding

If each of the values assigned to the variables named w and x in this program were rounded to the nearest integer, the result would be 4 and -4, not 3 and -3as produced by the program.

A. Compiler Error

## Explanation 4

Cannot cast a boolean type

A boolean type cannot be cast to any other type. This program produces the following compiler error:

 ```Ap042.java:13: inconvertible types found : booleanrequired: int int y = (int)x;```

D. B

## Explanation 3

The logical and operator

The logical and operator shown below

 The logical and operator `&&`

performs an and operation between its two operands, both of which must be of type boolean . If both operands are true, the operator returns true. Otherwise, it returns false.

The boolean negation operator

The boolean negation operator shown below

 The boolean negation operator !

is a unary operator, meaning that it always has only one operand. That operand must be of type boolean , and the operand always appears immediately to the right of the operator.

The behavior of this operator is to change its right operand from true to false, or from false to true.

Evaluation from left to right

Now, consider the following code fragment from this program.

 ```int x = 5, y = 6; if(!(x

The individual operands of the logical and operator are evaluated from left to right.

Consider the left operand of the logical and operator that reads:

 `!(x

The following expression is true

 `(x

In this case, x is less than y , so the expression inside the parentheses evaluates to true.

The following expression is false

 `!(x

The true result becomes the right operand for the boolean negation operator at this point.

You might think of the state of the evaluation process at this point as being something like

not true .

When the ! operator is applied to the true result, the combination of the two become a false result.

Short-circuit evaluation applies

This, in turn, causes the left operand of the logical and operator to be false .

At that point, the final outcome of the logical expression has been determined. It doesn't matter whether the right operand is true or false. Thefinal result will be false regardless.

No attempt is made to evaluate the right operand

Therefore, no attempt is made to evaluate the right operand of the logical and operator in this case.

No attempt is made to divide the integer variable x by zero, no exception is thrown, and the program doesn't terminate abnormally. It runs to completion anddisplays a B on the screen.

C. A

## Explanation 2

Short-circuit evaluation

Question 1 was intended to set the stage for this question.

This Question, in combination with Question 1 , is intended to help you understand and remember the concept of short-circuit evaluation.

What is short-circuit evaluation?

Logical expressions are evaluated from left to right. That is, the left operand of a logical operator is evaluated before the right operand of the sameoperator is evaluated.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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