C++ is a general-purpose programming language created by Bjarne Stroustrup in 1979. It has imperative, object-oriented and generic programming features. The structure of a C++ program includes preprocessor directives, a main() function, and a program body. Variables are declared with a data type and used to store and manipulate data. C++ supports various operators for arithmetic, relational, logical, and bitwise operations.

1. BASICS OF C++BASICS OF C++
Programming…Programming…

2. What is C++?
C++ (pronounced cee plus plus / si pl sˈ ː ʌ
pl s/) is a general-purpose programmingʌ
language. It has imperative, object-oriented
and generic programming features, while
also providing facilities for low-level memory
manipulation.

3. When was C++ Created?
Before the initial standardization in 1998, C+
+ was developed by Bjarne Stroustrup at
Bell Labs since 1979, as an extension of the
C language as he wanted an efficient and
flexible language similar to C, which also
provided high-level features for program
organization.

4. For What Purpose C++ is
used?
C++ is one of the most versatile languages
in the world. It is used nearly everywhere for
everything… systems programming
(operating systems, device drivers,
database engines, embedded, Internet of
Things, etc.)

5. What is the C++ Program?
C++ is an object oriented programming
(OOP) language, developed by Bjarne
Stroustrup, and is an extension of C
language. It is therefore possible to code C+
+ in a "C style" or "object-oriented style."

7. Structure of C++ Program:
The format of writing program in C++ is
called its STRUCTURE.
It consists of the following parts:
•Preprocessor directive
•Main() Function
•Program Body

8. Preprocessor Directive:
Preprocessor Directive is an instruction
given to the compiler before the execution of
actual program. Preprocessor directive is
also known as Compiler directive.
The preprocessor directive start with “Hash”
symbol ‘#.’

9. Include preprocessor :
Include preprocessor directive is used to
include header files in the program.
Syntax:
#include <iostream.h>

10. What are Header Files?
Header files contain definitions of Functions
and Variables, which is imported or used
into any C++ program by using the pre-
processor #include statement. Header file
have an extension ".h" which contains C++
function declaration and macro definition.

11. Syntax of Header files:
The syntax of header files is as follows:
#include <header_file_name>
Name of header file can also be used in
double quotes as follow:
#include “header_file_name”

12. Example:
#include <iostream.h>
The word “iostream” stands for input/output
stream. This header file contains the
definitions of built-in input and output
functions and objects.

13. main() Function:
The main() function is the starting point of a
C++ program. Each program must contain
main() function. If a program does not
contain main function, it can be compiled but
cannot be executed.

14. Syntax of main() function:
The syntax of main() function is as follows:
void main()
{
body of main function
}

15. Example:
The following example explains the basic
structure of C++ program:
#include<iostream.h> Preprocessor
void main() Main function
{
cout<<“Hello world”; Body Statement
}

16. What is Data Type in C++?
A Datatype actually describes you data like
what form of data you want to create (It may
be integer, character, floating point
number, string etc.) In the context of C++,
you can make many types of data that are
mentioned above.

17. Cont..
To make integer datatype, you type int and
then write its name (called variable name).
To create floating point datatype , you type
float and then write its variable. That is
actually a syntax of C++. (It may differ for
other languages).

18. Cont…
• int- integer, it is of 2 or 4 bytes dependent
on machine.
• char- character type (used to store
characters and strings), one byte.
• float- used to store floating point numbers,
4 bytes.
• double- used to store high precision
floating point numbers, 8 bytes.

19. Variables:
A Variable is a named memory location or
memory cell. It is used to store program`s
input data. The value of variable may
change during the execution of program.
However, the name of variable cannot be
changed.

20. How variables created?
The variables are created in RAM. RAM is a
temporary memory. That is why the data
stored in variables is also temporary.
The data stored in the variable is
automatically removed when program ends.

21. Variable Declaration:
The process of specifying the variable name
and its type is called “Variable
Declaration”.
Syntax:
data_type variable_name;
Example:
int marks;
float average;

22. Variable Initialization:
The process of assigning a value to a
variable at the time of declaration is known
as “Variable initialization”.
The equal sign ‘=‘ is used to initialize a
variable. Variable name is given on left side
and value is given on the right side of equal
sign.

23. Syntax:
The syntax of initializing a variable is as
follows:
data_type variable_name =value;
Example:
int n =100;
float a=50.73;

24. What are Operators?
An operator is a symbol that tells the
compiler to perform specific mathematical or
logical manipulations. C++ is rich in built-in
operators and provides the variety of
operators: Arithmetic Operators. Relational
Operators.

25. Cont…
The operators can be categorized as follow:
Unary Operator:
A type of operator that works with one
operand is known as unary operator.
Example:
-,++,--, -a, N++, --x

26. Cont…
Binary Operator:
A type of operator that works with two
operands is known as Binary Operator.
Example:
+,-,*,/,%
a + b;
x/y;

27. What are Arithmetic
Operator?
C++ uses operators to do arithmetic. It
provides operators for five basic arithmetic
calculations: addition, subtraction,
multiplication, division, and taking the
modulus. Each of these operators uses two
values (called operands) to calculate a final
answer

28. Example..
Suppose we have 2 variables A & B where
A=10 & B=5. Arithmetic operation can be
used on A & B as follows:
Operations Result
A + B 15
A - B 5
A * B 50
A / B 2
A % B 0

29. What is Relational operator?
• In computer science, a relational
operator is a programming language
construct or operator that tests or defines
some kind of relation between two entities.
These include numerical equality (e.g., 5 =
5) and inequalities (e.g., 4 ≥ 3).

30. Assignment Statement:
A statement that assigns a value to a
variable is known as “Assignment
Statement”.
Syntax:
Variable = expression;
“=” is the assignment operator.
Example:
A=100;
C=A+B;

31. Compound Assignment
Statement:
An assignment statement that assigns a
value to many variables is known as
“Compound Assignment” statement.
Example:
A=B=10;
x = y= z= 100;

32. Compound Assignment
Operator:
C++ language provides Compound
Assignment operator that combines
assignment operator with arithmetic
operators.
Syntax:
Variable op=expression;
Example:
N+=10; is equivalent to N=N+10;

33. Increment Operator:
The increment operator is used to increase
the value of a variable by 1. It is denoted by
the symbol “++”.
Increment operator can be used as follows:
•Prefix form
•Postfix form

34. Prefix & Postfix Form:
In Prefix form, the increment operator is
written before the variable as follows:
++y;
In Postfix form, the increment operator is
written after the variable as follows:
y++;

35. Decrement Operator:
The Decrement operator is used to
decrement the value of a variable by 1. It is
denoted by the symbol “—”.
Decrement operator can be used in two
forms:
•Prefix form
•Postfix form

36. Prefix & Postfix Form:
In prefix form, decrement operator is written
before the variable as follows:
--y;
In postfix form, decrement operator is
written after the variable as follows:
y--;