# 0.1 Learning objects for control structures in java  (Page 2/5)

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## Conditional expressions

Concept A conditional expression is a shorthand for an if-statement that assigns different values to one variable:

if (expression) var = value1; else var = value2;

This can be rewritten more concisely as:

var = (expression) ? value1 : value2;

The boolean-valued expression is evaluated: If the result is true, value1 is assigned to var ; if not, value2 is assign to var .

Program: Control02.java

// Learning Object Control02 //    conditional expressionspublic class Control02 {     public static void main(/*String[] args*/) {         int year = 2001;        int month = 2;         int days;        if (month == 2)             days = (year % 4 == 0) ? 28 : 29;        else if (month == 4 || month == 6 ||                 month == 9 || month == 11)            days = 30;         else            days = 31;         System.out.println(days);    } }

The program computes the number of days in a month taking leap years into account.

• The variables are allocated and the first two, year and month , are given initial values.
• The expression month == 2 evaluates to true, so the statement following the expression is executed. Jeliot will display Choosing then-branch to emphasize this.
• The inner statement is an assignment statement with a conditional expression. The expression is evaluatedand its result is false, so the value after the colon is assigned to the variable. Jeliot will display Choosing else-branch .
• The value of days is printed.

Exercise Complete the program with the correct computation for leap years: a year divisible by 100 is not a leap year unless itis divisible by 400.

Exercise Rewrite the entire if-statement as nested conditional expressions.

## While loops

Concept A loop enables the execution of a statement (including a block of statements within braces) an arbitrary number of times.This statement is called the loop body . In a while loop, an expression is evaluated before each execution of the loop body,and loop body is executed if and only if the expression evaluates to true.

Program: Control03.java

// Learning Object Control03 //    while loopspublic class Control03 {     static int LIMIT = 100;    public static void main(/*String[] args*/) {        int factorial = 1;         int n = 1;        while (factorial < LIMIT) {             System.out.println(factorial);            n++;             factorial = factorial * n;        }     }}

This program prints all factorials less than LIMIT = 100 , namely, $1!=1$ , $2!=2$ , $3!=6$ , $4!=24$ .

• The static constant and the two variables are allocated and initialized.
• Then, and each time the keyword while is reached, the expression is evaluated. If it is true, execution proceeds with the loop body, andJeliot displays Entering the while loop the first time and Continuing the while loop on subsequent occasions.
• The statements of the loop body are executed. They print the value of the current factorial, increment the counterand compute the new factorial; then, control returns to the while-expression.
• If and when the expression evaluates to false, execution proceeds with the statement following the loop body.Jeliot displays Exiting the while loop .

how can chip be made from sand
are nano particles real
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
no can't
Lohitha
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
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
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
how did you get the value of 2000N.What calculations are needed to arrive at it
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