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The header file for the iostream class is iostream.h.

The #include statement is one of the several preprocessor directives that are used with C++.

The preprocessor is a program that runs before the compiler. When it encounters an #include statement, the preprocessor places the entire contents of the designated file into the current file.

Preprocessor directives and include statements allow the current file to use any of the classes, functions, variables, and other code contained within the included file.

Example: To include the iostream.h file you use the following statement:


An i/o manipulator is a special function that can be used with an i/o statement. The endl i/o manipulator is part of the iostream classes and represents a new line character.


cout<<“Program type: console application”<<endl;

cout<<“Create with: Visual C++ “<<endl;

cout<<“Programmer: Don Gesselin”<<endl;

All statements in C++ must end with a semicolon. Large statements can span multiple lines of code.


cout<<“Program type: console application,”

<<“Create with: Visual C++ “

<<“Programmer: Don Gesselin”;


Comments are lines that you place in your code to contain various type of remarks. C++ support two types of comments: line and block.

C++ line comments are created by adding two slashes (//) before the text you want to use as a comment.

Block comments span multiple lines. Such comments begin with /* and end with the symbols */.


void main()



This line is part of the block comment.

This line is also part of the block



cout<<“Line comment 1 “;

cout<<“Line comment 2 “;

// This line comment takes up an entire line.


All programs should contain comments. They are

remarks, insights, wisdom in code without affecting the program. The compiler ignores comments


Data types and operators

Data types

A data type is the specific category of information that a variable contains.

There are three basic data types used in C++: integers, floating point numbers and characters.


An integer is a positive or negative number with no decimal places.

- 259 -13 0 200

Floating Point Numbers

A floating point number contains decimal places or is written using exponential notations.

-6.16 -4.4 2.7541 10.5

Exponential notation, or scientific notation is a way of writing a very large numbers or numbers with many decimal places using a shortened format.

2.0e11 means 2*1011

C++ supports three different kinds of floating-point numbers:

  • float (i.e. single precision numbers),
  • double (i.e. double precision numbers)
  • long double.

A double precision floating-point number can contain up to 15 significant digits.

The Character Data Type

To store text, you use the character data type. To store one character in a variable, you use the char keyword and place the character in single quotation marks.


char cLetter = ‘A’;

Escape sequence

The combination of a backlash (\) and a special character is called an escape sequence. When this character is placed directly in front of a select group of character, it tells the compiler to escape from the way these characters would normally be interpreted.

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
Got questions? Join the online conversation and get instant answers!
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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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