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The break statement violates pure structured programming principles because it provides a second, nonstandard exit from a loop.

However, it is useful and valuable for breaking out of loops when an unusual condition is detected.

Continue statements

The continue statement halts a looping statement and restarts the loop with a new iteration.

while( count<30)


cout<<“Enter a grade: “;


if (grade<0 || grade>100)


total = total + grade;



In the above program, invalid grades are simply ignored and only valid grades are added to the total.

The null statement

All statements must be terminated by a semicolon. A semicolon with nothing preceding it is also a valid statement, called the null statement. Thus, the statement


is a null statement.


if (a>0)

b = 7;

else ;

The null statement is a do-nothing statement.

For loops

The for statement is used for repeating a statement or series of statements as long as a given conditional expression evaluates to true.

One of the main differences between while statement and for statement is that in addition to a conditional expression, you can also include code in the for statement

  • to initialize a counter variable and
  • changes its value with each iteration

The syntax of the for statement:

for ( initialization expression; condition; update statement){



In its most common form, the initialization expression consists of a single statement used to set the starting value of a counter variable, the condition contains the maximum or minimum value of the counter variable can have and determines when the loop is finished, and the update statement provides the increment value that is added to or subtracted from the counter variable each time the loop is executed.

The flowchart of the for statement is given below.

Flow chart of the for statement



int main()


int sum = 0;

for (int number = 2; number<= 100; number += 2)

sum += number;

cout<<“Sum is “<<sum<<endl;

return 0;


The output of the above program:

Sum is 2550


In this example, we have to solve the following problem:

A person invests $1000.00 in a saving account with 5 percent interest. Assuming that all interest is left on deposit in the account, calculate and print the amount of money in the account at the end of each year for 10 years. Use the following formula for determining these amounts:

a = p(1 + r)^n

where p is the original amount invested, r is the annual interest rate and n is the number of years and a is the amount on deposit at the end of the nth year.




int main()


double amount,

principal = 1000.0,

rate = 0.05;


<<"Amount on deposit"<<endl;

cout<<setiosflags(ios::fixed | ios::showpoint)<<setprecision(2);

for (int year = 1; year<= 10; year++)


amount = principal*pow(1.0 + rate, year);




return 0;


The output of the above program:

YearAmount on deposit

1 1050.00

  1. 1102.50
  2. 1157.62
  3. 1215.51
  4. 1276.28
  5. 1340.10
  6. 1407.10
  7. 1477.46
  8. 1551.33
  9. 1628.89

Nested loops

In many situations, it is convenient to use a loop contained within another loop. Such loops are called nested loops .

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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Source:  OpenStax, Programming fundamentals in c++. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10788/1.1
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