Introduction to c++ ppt 1

INTRODUCTION TO C++
Prof. K ADISESHA (Ph. D)

INTRODUCTION TO
C++
PROGRAMMING
introduction
Characteristics of C++
C++ Character Set
C++ Tokens
Data Types of C++
2
C++ PROGRAMMING
Prof. K. Adisesha (Ph. D)
I/O Operators of C++

Introduction
3
History of C++:
The C++ programming language was created by Bjarne Stroustrup and his team at
Bell Laboratories (AT&T, USA) to help implement simulation projects in an object-
oriented and efficient way.
➢ C++ is a superset of C because; any valid C program is valid C++ program too but not
the vice versa is not true.
➢ C++ can make use of existing C software libraries with major addition of “Class
Construct”.
➢ This language was called “C with classes” and later in 1983, it was named “C++” by
Rick Mascitii. As the name C++ implies, C++ was derived from the C programming
language: ++ is the increment operator in C.

Introduction
4
OOPs characteristics
➢ Modularity: Module is a logically self-contained unit that can be tested and executed independently.
➢ Abstraction: It represents the essential features of an entity without including explanations or any
background details about it.
➢ Data Encapsulation: Wrapping of data and functions into a single unit is called data encapsulation.
➢ Inheritance: The process by which objects of one class acquires the properties of the objects of
another class.
➢ Polymorphism: The ability for a message to be processed in more than one form.
➢ Dynamic Binding: Linking of a procedure call to the code to be executed when it is called.
➢ Message Passing: Passing message objects and invoking the function by the object by sending a
message is known as message passing.

Introduction
5
OOPs Benefits
➢ OOPs model the real world entity very well.
➢ Inheritance eliminates the redundancy (repetition) of code and hence supports code
reusability.
➢ Data hiding helps to build secured programs.
➢ Multiple instances (objects) can be created.
➢ Work can be divided easily.
➢ OOPs can be easily upgraded from small to large systems.
➢ Complexity can be easily managed.
➢ Message passing concept helps the objects to communicate and share data.

Introduction
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OOPs Applications
➢ Object oriented databases.
➢ Hypermedia, expert text and hypertext.
➢ Artificial intelligence and expert systems.
➢ Decision support systems and office automation systems.
➢ Parallel programming and neural networks.
➢ CAD, CAM, CIM systems.
➢ Simulation and modeling.

Introduction
Why Use C++
➢ C++ is one of the world's most popular programming languages.
➢ C++ can be found in today's operating systems, Graphical User Interfaces, and embedded
systems.
➢ C++ is an object-oriented programming language which gives a clear structure to programs
and allows code to be reused, lowering development costs.
➢ C++ is portable and can be used to develop applications that can be adapted to multiple
platforms.
➢ C++ is fun and easy to learn!
➢ As C++ is close to C# and Java, it makes it easy for programmers to switch to C++ or vice
versa
7

Introduction
8
Translating a C++ program
➢ Computers execute binary instructions.
➢ These binary instructions are known as machine instructions or machine code.
➢ The program creation process consists of the following steps:
Step 1 – Write the program in a computer language humans can read and understand (like C++),
Step 2 – Save the programs in text files as (.cpp) extension. Programs can be a few lines long and
reside in one file or can consist of many millions of lines of code and span thousands of files,
Step 3 – Run the source code files through a program called a compiler to generate object code for the
target computer,
Step 4 – Run the object files through a program called a linker to produce an executable image.

Introduction
9
Translating a C++ program
➢ C++ Install IDE: download and Install Turbo C++ or Install Codeblocks
➢ The program execution process consists of the following steps:

Introduction
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General Structure of C++ Program.
 Different programming languages have their own format of coding.
 The basic components of a C++program are:
◼ Comments or Documentation Section
◼ Pre-processor Directives (Linker Section):
◼ Definition
◼ Global Declaration
◼ main ( ) function
◼ Declarations
◼ Statements

Introduction
11
General Structure of C++ Program
➢ The basic components of a C++program are:

12
Characteristics of C++:
Object-Oriented Programming:
➢ It allows the programmer to design applications like a communication between object
rather than on a structured sequence of code. It allows a greater reusability of code in a
more logical and productive way.
Portability:
➢ We can compile the same C++ code in almost any type of computer & operating
system without making any changes.
Modular Programming:
➢ An application’s body in C++ can be made up of several source code files that are
compiled separately and then linked together saving time.

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C Compatibility:
➢ Any code written in C can easily be included in a C++ program without making any
changes.
Speed:
➢ The resulting code from a C++ compilation is very efficient due to its duality as high-
level and low-level language.
Machine independent:
➢ It is a Machine Independent Language.

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Flexibility:
➢ It is highly flexible language and versatility.
Wide range of library functions:
➢ It has huge library functions; it reduces the code development time and also reduces
cost of software development.
System Software Development:
➢ It can be used for developing System Software Viz., Operating system, Compilers,
Editors and Database.

C++ Character Set
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C++ Character Set:
Character Set means the valid set of characters that a language can recognizes.
➢ The character set of C++ includes the following:

C++ Tokens
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C++ Tokens:
The smallest individual unit in a program is known as token.
➢ These elements help us to construct statements, definitions, declarations, and so on,
which in turn helps us to construct complete program.
➢ Tokens used in C++ are:
❖ Identifier
❖ Reserved Keywords
❖ Constants or Literals
❖ Punctuators
❖ Operators

C++ Tokens
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C++ Identifier:
Identifiers is a name given to programming elements such as variables, functions,
arrays, objects, classes, etc.
➢ It contains letters, digits and underscore.
➢ C++ is a case sensitive; it treats uppercase and lowercase characters differently.
➢ The following are some valid identifiers:
▪ Adisesha
▪ time_table
▪ s2e2r3
▪ _dos _HJI3_JK

C++ Tokens
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C++ Identifier:
Rules to be followed while creating identifiers.
➢ Identifiers are a sequence of characters which should begin with the alphabet either
from A-Z (uppercase) or a-z (lowercase) or _ (underscore).
➢ C++ treats uppercase and lowercase characters differently. For example, DATA is not
same as data.
➢ No Special character is allowed except underscore “_”.
➢ Identifier should be single words i.e. blank spaces cannot be included in identifier.
➢ Reserved Keywords should not be used as identifiers.
➢ Identifiers should be of reasonable length.

C++ Tokens
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C++ Keywords:
Keyword is a predefined word that gives special meaning to the complier. The
programmer is not allowed to change its meaning.
➢ These are reserve for special purpose and must not be used as identifier name.
➢ Example:
cin, cout, for, if, else, this,
do, float, while, switch etc.,

C++ Tokens
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C++ Keywords:
There are keywords in C++ as mentioned below:

C++ Tokens
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Literals: A Literals/ constant are identifiers whose value does not change
during program execution.
➢ Constants are sometimes referred to as literal.
➢ A constant or literal my be any one of the following:
❖ Integer Constant
❖ Floating Constant
❖ Character Constant
❖ String Constant

Integer Constant:
➢ An integer constant is a whole number, which can be either positive or negative.
➢ They do not have fractional part or exponents.
➢ We can specify integer constants in:
❖ Decimal Integer Constant int a = 120; //Decimal Constant
❖ Octal Integer Constant int b = 0374; //Octal Constant
❖ Hexadecimal Integer Constant int c = -0XABF; //Hexadecimal Constant
❖ Unsigned Constant unsigned d = 328u; //Unsigned value
C++ Tokens
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C++ Tokens
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Floating Point Constant:
➢ Floating point constants are also called as “real constants”.
➢ These values contain decimal points (.) and can contain exponents.
➢ They are used to represent values that will have a fractional part and can be
represented in two forms (i.e. fractional form and exponent form)
➢ We can specify Floating Point constants in:
❖ float a=23.46 // equal to 23.46 x 100 = 23.46 x 1 = 23.46
❖ float b=26.126

Character constants: are specified as single character enclosed in pair of single
quotation marks.
❖ For example char ch = ‘P’;
➢ There are certain characters used in C++ which represents character constants called as
escape sequence which starts with a back slash ( ) followed by a character.
C++ Tokens
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C++ Tokens
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String Constants:
➢ A string constant consists of zero or more character enclosed by double quotation
marks (“ ”).
➢ Multiple character constants are called string constants and they are treated as an array
of char.
➢ By default compiler adds a special character called the “Null Character” (0) at the end
of the string to mark the end of the string.
➢ Example:
◼ char str[25] = “Hello Adisesha” ;
◼ This is actually represented as char str[25] = “Hello Adisesha0” in the memory

C++ Operators: Operators are used to perform operations on variables and values.
❖ Example: int x = 100 + 50;
➢ C++ Operators Types:
❖ C++ divides the operators into the following groups.
❖ Arithmetic operators
❖ Assignment operators
❖ Comparison operators
❖ Logical operators
❖ Bitwise operators
.
C++ Operators
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Arithmetic Operators
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➢ Arithmetic operators are used to perform common mathematical operations.

Assignment Operators
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➢ Assignment operators are used to assign values to variables.

Relational Operator
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➢ Comparison operators are used to compare two values.
➢ The return value of a comparison is either true (1) or false (0).

Logical Operators
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➢ Logical operators are used to determine the logic between variables or values.

Bitwise Operators
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➢ A Bitwise operators are used in bit level programming.

Classification of Operators
32
➢ Operators may also be classified on the number of operands they act on either:
❖ Unary Operators
◼ Example: a++, a+1
❖ Binary Operators
◼ Example: x = x – 10;
❖ Ternary Operators
◼ Example: x = (a>b) ? a:b;

C++ Operators
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Special Operator :
➢ An expression is a combination of opcode and operand.
➢ Some special operators used in C++ programming are:

Punctuators
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➢ Punctuators in C++ have syntactic and semantic meaning to the compiler.

Structure of C++ Program
35
General Structure of C++ Program.
 Different programming languages have their own format of coding.
 The basic components of a C++program are:
◼ Comments or Documentation Section
◼ Pre-processor Directives (Linker Section):
◼ Definition
◼ Global Declaration
◼ main ( ) function
◼ Declarations
◼ Statements

Structure of C++ Program
36
General Structure of C++ Program
➢ Different programming languages have their own format of coding.
➢ The basic components of a C++program are:

C++ Comments
37
C++ Comments
Comments can be used as non-executable statement to explain C++ code, and to make
it more readable.
➢ It can also be used to prevent execution when testing alternative code.
➢ Comments can be:
❖ singled-lined: Single-line comments start with two forward slashes (//).
Example:
❖ multi-lined.: Multi-line comments start with /* and ends with */.
Example:

C++ Linker Section
38
Linker Section in C++
The linker is a program that makes executable files.
➢ The linker resolves linkage issues, such as the use of symbol hash (#) defined in one
translation unit.
➢ The C++ preprocessor directives programming skills that should be acquired:
❖ Able to understand and use #include.
❖ Able to understand and use #define.
❖ Able to understand and use macros and inline functions.

Library Functions in C++
Built-in functions are also known as library functions.
➢ We need not to declare and define these functions as they are already written in the
C++ libraries such as iostream, cmath etc.
C++ Library Functions
39

Built-in functions for String manipulation are:
40

41

C++ Main function
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Main function section in C++
The starting point of all C++ programs is the main function.
➢ This function is called by the operating system when your program is executed by the
computer.
int main( )
{
cout << "Hello World" << endl; //Function body section
return 0;
}
❖ { signifies the start of a block of code, and } signifies the end.

Data Types
43
Data Types in C++:
Data Types can be defined as the set of values, which can be stored in a variable along
with the operations that can be performed on those values.
 C++ defines several types of data and each type has unique characteristics.
 C++ data types can be classified as:
❖ The fundamental data type(built-in data)
❖ Derived Data type
❖ User-defined data type

Data Types:
➢ C++ defines several types of data and each type has unique characteristics.
➢ C++ data types can be classified as:
Data Types
44

Data Types
45
Basic Data Types:char type
The char type: It is character data type to store any character from the basic character set.
➢ Characters are enclosed in single quotation marks (‘). ‘A’, ‘a’, ‘b’, ‘9’, ‘+’ etc. are
character constants.
❖ When a variable of type char is declared, the compiler converts the character to its equivalent
ASCII code.
❖ A character is allocated only 1 byte (8 bits) of memory space.
❖ The general form of a character declaration is: char variable_list;
➢ Example: char alpha=’a’;

Data Types
46
Basic Data Types:int type
The int type: The int type is used to store integers. Integers are whole numbers without
any fractional parts.
➢ An integer is allocated 2 bytes (16 bits) of memory space.
➢ The operations include addition, subtraction, multiplication, division, remainder etc.
➢ The integer can be positive or negative values and the ranges of number we can store
are from - 32786 to 32767.
➢ This includes number such as:
❖ 45 and -9 are integers.
❖ 5.2 is not an integer because it contains a decimal point.

Data Types
47
Basic Data Types:float type
The float type: This represents the number with fractional part i.e. real numbers.
➢ The float type is used to store real numbers.
➢ Float is allocated 4 bytes (32 bits) of memory space.
➢ Number such as 1.8, 4.5, 12e-5 and -9.66 are all floating-point numbers.
➢ The range of numbers we can store from -34e-38 to 3.4e38.
➢ The general form of a float declaration is: float variable_name;
➢ Example:
❖ float a=5.5;

Data Types
48
Basic Data Types:double type
The double type: The double and float are very similar.
➢ The float type allows you to store single precision floating point numbers, while the
double keyword allows you to store double precision floating point numbers.
➢ Its size is typically 8 bytes of memory space. The range of numbers we can store are
from -1.7e308 to 1.7e308.
➢ The general form of a double declaration is: double variable_list;
➢ Example: double a = 5.5e-7; //a is equivalent to 5.5x10-7
❖ float a=5.5;

Data Types
49
Basic Data Types:bool type
The bool type: The bool type has logical value true or false.
➢ The identifier true has the value 1, and the identifier false has the value 0.
➢ The general form of a bool declaration is: bool variable_name;
➢ Example:
❖ bool legal_age=true;
❖ The statement legal_age= (age>=21);
✓ assigns the value true if age is greater than or equal to 21 or else it returns the value
false

Data Types
50
Basic Data Types:void type
The void type : The void data type has no values and no operations.
➢ In other words, both the set of values and set of operations are empty.
➢ In this declaration the main function does not return any value.
➢ Example:
❖ void main( )
{
Statements;
}

Basic Data Types:
➢ The data type specifies the size and type of information the variable will
store.
➢ Example:
int myNum = 5; // Integer (whole number)
float myFloatNum = 5.99; // Floating point number
double myDoubleNum = 9.98; // Floating point number
char myLetter = ‘A'; // Character
bool myBoolean = true; // Boolean
string myText = "Hello"; // String
Data Types
51

Data Types
52
Basic Data Types:
➢ The data type specifies the size and type of information the variable will
store.

Data Types
53
Derived data types:
These data types are constructed using simple or fundamental data types.
➢ Derived data types emphasize on structuring of a group of homogeneous (same type)
data items.
➢ These data types includes:
❖ Arrays
❖ Functions
❖ Pointers
❖ References

Data Types
54
User defined data types:
These data types are constructed by user using simple or fundamental data types.
➢ User defined data types emphasize on structuring of a group of homogeneous (same
type) or heterogeneous (different type) data items.
➢ Some user defined data types include
❖ Enumerated
❖ Structure
❖ Union
❖ Class

Data Types
55
Enumerated data type:
Enumerated data type: An enumeration is a user defined type consisting of a set of named
constants called enumerators.
➢ enum is a keyword that assigns values 0, 1, 2…… automatically.
➢ This helps in providing an alternative means for creating symbolic constants.
➢ The syntax for enum is as follows:
enum [tag] { enum – list} ; //for definition for enumerated type
➢ Example : enum choice { bad, satisfactory, good, very_good};
choice mychoice;

Data Types
56
C++ Modifier Types:
A modifier is used to alter the meaning of the base type so that it more precisely fits the
needs of various situations.
➢ C++ allows the char, int, and double data types to have modifiers preceding them.
➢ The data type modifiers are listed here −
❖ Signed Ex: unsigned x;
❖ Unsigned unsigned int y;
❖ long
❖ Short

Converting an expression of a given type into another type is known as typecasting or
type conversion.
➢ Type conversions are of two types, they are:
◼ Implicit Conversion: They are automatically performed when a value is copied to a
compatible type.
 Example: short a = 2000;
int b;
b = a;
◼ Explicit Conversion: Many conversions, especially those that imply a different
interpretation of the value, require an explicit conversion.
 Example: short a = 2000;
int b;
b = (int) a; //c-like cast notation
Type Conversion
57

Input & Output Operators
58
➢ The input output operations are done using library functions cin and cout objects of
the class iostream.
➢ Using the standard input and output library, we will able to interact with the user by
printing message on the screen and getting the user’s input from the keyboard.
❖ A stream is an object where a program can either insert/extract characters to/from
it.
❖ The standard C++ library includes the header file iostream, where the standard
input and output stream objects are declared.

59
Input Operators:
➢ Input Operator “>>”: The standard input device is usually the keyboard.
➢ Input in C++ is done by using the “stream extraction” (>>) on the cin stream.
➢ “cin” stands for “console input”.
➢ Example: int age;
cin>>age;

60
Output Operator:
 Output Operator “<<”: The standard output device is the screen (Monitor).
 Outputting in C++ is done by using the object followed by the “stream insertion”
(<<).
 “cout” stands for console output
 Example: cout<<”sum”; //prints sum
cout<<sum; //prints the content of the variable sum;

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Cascading of I/O Operators:
 If a program requires more than one input variable then it is possible to input these
variables in a single cin statement using multiple stream extraction “>>” operators.
 Example: cout<<”Enter the two number”;
cin>>a>>b;
 If a program requires more than one output result then this can be done using a single
cout statement with multiple stream insertion “<<“ operators.
 This is called cascading of input & output operators.
 Example: cout<<”Entered the two number”<<a<<b<<endl;
cout<<”The sum of two number is”<<sum<<endl;

Manipulators
62
Formatted Output (Manipulators): :
➢ Manipulators are the operators used with the insertion operator “<<“ to format the data
display.
➢ To use manipulator it is must to include header file <iomanip.h>
❖ endl
❖ setw()
➢ Example: endl manipulator: causes a line feed to be inserted. It has same effect as using new
line character “n”.
cout<<”Entered the two number”<<a<<b<<endl;
The setw( ) manipulator sets the width of the field assign for the output.
cout<<setw(6)<<”R” ; Output: _ _ _ _ _ R

Formatted Output (Manipulators):
➢ Manipulators are the operators used with the insertion operator “<<“ to format the data display.
➢ Program: To find the sum of two numbers:
#include<iostream.h>
#include<iomanip.h>
void main( )
{ int a, b, add;
clrscr( );
cout<<”Enter the two numbers”<<endl;
cin>>a>>b;
add = a + b;
cout<<”The sum of two number is”<<setw(6)<<sum<<endl;
getch(); }
Manipulators
63

Formatted Output (Manipulators):
Manipulators
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Discussion
65
Queries ?
Prof. K. Adisesha
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Introduction to c++ ppt 1

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