The document introduces programming and the C++ language. It explains that a program is a set of instructions given to a computer in a programming language to perform tasks. High-level languages like C++ were created because computers only understand binary and it is impossible for humans to program in binary. The document then covers the anatomy of a simple "Hello World" C++ program, including main functions, header files, output statements, strings, and terminators. It concludes by explaining how C++ source code is compiled into machine code and executed.

1. INTRODUCTION TO
PROGRAMMING

2. WHAT IS A PROGRAM?
• A program is a set of instructions in a programming
language given to a computer to perform some useful
task.

3. WHY DO WE NEED TO LEARN A
PROGRAMMING LANGUAGE?
• A computer is just a machine. It cannot do anything till it is told
to do so. Like a fan for example will not start until we switch it
on.
• So in order to be able to make it work we need to give it specific
instructions.

4. INSTRUCTING THE
COMPUTER IN SIMPLE
LANGUAGE
• It will not understand.
We have to
communicate with
this machine in the
language it
understands.
Add the numbers 4 and 5

5. WHAT IS HIGH LEVEL LANGUAGE?
• The computer understands only binary language or machine language
which contains only two digits, 0 and 1.
• These are 0 (means off) and 1 (means on).
• It is humanly impossible to communicate all the commands or
instructions using only these two numbers.
• So high level languages were created. Such languages are
considered high-level because they are closer to human languages and
further from machine languages.

6. C++ PROGRAMMING LANGUAGE
C++ is a high level
programming
language
01
It was created by
Bjarne Stroustrup.
02
It is a versatile,
powerful object
oriented language
03

7. THE FIRST C++
PROGRAM
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}

8. THE PREPROCESSOR
DIRECTIVE
#include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
The symbol # is
the Preprocessor
Directive
A preprocessor
directive is a direct
command to the
compiler
To perform an action
Preprocessor
Directive

9. THE INCLUDE
KEYWORD
#include<iostream.h>
void main( )
{
cout<< “Hello World”;
}
The include keyword
gives a command to
include a file, in this
case a header file,
iostream.h

10. THE IOSTREAM.H
HEADER FILE
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
The iostream .h header
file stands for Input
Output stream file
which contains
commands and
instructions necessary
to connect our
program to the input
and output streams.
A header file is a file
with
extension .h which
contains C++ function
declarations and

11. THE MAIN()
FUNCTION
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
Every c++ program
must have a main()
function as the
execution begins here.
In fact main() is the
only self executing
function in c++.
Since it is a function it
must contain a pair of
brackets and must be
preceded by a return
type, void , in this case.

12. THE MAIN() BODY :
BRACES
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
The body of main()
consists of executable
statements within a
pair of curly braces. { }
Whatever is written in
these braces is the
code that is executed
when the program is
run.

13. THE COUT
STATEMENT
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
In this case the main()
function consists of a
single executable
statement;
cout<< “Hello World”;
cout stands for
console output. It is
actually a command to
display something on
the output console;
the screen in this case.

14. THE INSERTION(<<)
OPERATORS.
# include <iostream.h>
void main( )
{
cout << “Hello World”;
}
cout<< “Hello World”;
The << symbol are
known as insertion
operators. They are
used to direct the
output to the console
in this case.

15. THE STRING IN
DOUBLE QUOTES” ”
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
“Hello World ” is a
constant string. It is
displayed as a
message on the
screen. Any text or
number or symbol
written within a pair of
“ ” apostrophes is
displayed as it is on
the screen.

16. THE STATEMENT
TERMINATOR(;)
# include <iostream.h>
void main( )
{
cout<< “Hello World” ;
}
The semicolon ; is a
statement terminator
in c++. It is used at the
end of various
executable statements
and declarations to
mark the end of a
statement.

17. C++ source code
# include <iostream.h>
void main( )
{
cout<< “Hello World”;
}
Hello World
Output
THE EXECUTION OF THE FIRST
PROGRAM

18. HOW THE C++ PROGRAM
IS EXECUTED
Executable code(running the program)
First.exe
Machine language code(compiler)
First.obj
Source code( Create on Editor)
First.cpp
The c++ source code is written on the c++ editor. When
it is saved a file with the extension .cpp is generated
It is then compiled, wherein the compiler converts the
high level program to machine language. A file with the
extension .obj is generated
The machine code is then executed to generate an
executable file. A file with extension .exe is executed.
NOTE : the process of compilation also generates syntax
errors if any.