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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:

#include<iostream.h>

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.

Example:

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.

Example:

cout<<“Program type: console application,”

<<“Create with: Visual C++ “

<<“Programmer: Don Gesselin”;

Comments

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 */.

Example:

void main()

{

/*

This line is part of the block comment.

This line is also part of the block

comment.

*/

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.

Integers

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.

Example:

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

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
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.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele 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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