c++ workshop ppt

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C++ -Object Oriented Programming

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Introduction to C++

C++ is an object oriented programming language.

It is an extension of c.

It was developed by Bjarne Stroustrup.

Combination of more than one programming language.

It is mainly used for creating complicated applications.

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Evolution of C++

The combination Simula67 and C.

It was named as ‘C with classes’.

In 1983,the name was changed to C++.

C++ is an extended version of C.

C++ is a superset of C.

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Programming Paradigms

A programming paradigm is a model of programming based on distinct concepts that shapes the way programmers design, organize and write programs.

- Monolithic Programming- Procedural Programming- Structured Programming

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Monolithic Programming

- Monolithic Programming indicates the program which contain a single function for the large program.

- Monolithic programming will not divide the program and it is a single thread of execution.

- In monolithic programming data variables are declared globally and the statements are written in sequence.

- The program contains jump statements such ad goto.

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Procedural Programming

- A procedural programming language is one where programs are organized into blocks of code called variously "subroutines", "functions", or "procedures", each of which handles one particular task.

- FORTRAN and COBOL

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Structured Programming

- A computer programming technique that follows a top down design approach with block oriented structures.

- In structured programming languages such as PASCAL and C larger programs are developed.

- Programs are divided into multiple sub modules and procedures.

- Each module has its own set of local variable.

- User-defined data types are introduced.

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Object Oriented Technology

Object-oriented programming (OOP) is a programming paradigm that uses "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs.

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KEY CONCEPTS OF OBJECT-ORIENTED PROGRAMMING

There are several fundamental or key concepts in object-oriented programming.

1.Classes2.Objects3.Method4.Data Abstraction5.Encapsulation6.Inheritance7.Polymorphism8.Reusability

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Objects

Objects are primary run-time entities in object-oriented programming.

An object is a real world thing or concept expressed as a software representation.

Hardware,software,documents,human beings and concepts are example of objects.

Objects are instance of a class.

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Classes

A class is grouping of objects having identical properties,common behavior and shared relationship.

The entire group of data and code of an object can be built as a user-defined data type using class.

Objects are variables of a type class.

A class is a model of the object.

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class A

{

private:

data member1;

data member2;

data member(n);

public:

method1();

method2();

};

Members

Methods or Member functions

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Objects and their properties

Class : carProperties : company,model,color and capacity.Actions : speed(),average() and break()

Class : computerProperties : brand,price,monitor,hard diskActions : processing(),display() and printing()

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Example

Employee(Real World)

Class Employee

EmpidName

Address

Emp1

Emp2

Emp3...

Emp n

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Method

Method is a set of procedural statements for achieving the desired result.

It performs different kinds of operations on different data types.

It is also known as functions.

Class : computerProperties : brand,price,monitor,hard diskActions : processing(),display() and printing()

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Data Abstraction

Abstraction refers to the act of representing essential features without including the background details or explanations.

Classes use the concept of abstraction and are defined as a list of abstract attributes.

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Encapsulation

The packing of data and functions into a single component is known as encapsulation.

C++ supports the features of encapsulation using classes.

The data is not accessible by outside functions.

Data’s can be accessed only the functions defined inside the class.

Data hiding can be accomplished with encapsulation.

By data hiding an object can be used by the user without knowing how it works internally.

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Inheritance

Inheritance is an important and powerful concept in object oriented technology.

Inheritance is the method by which objects of one class get the properties of objects of another class.

It means,existing class can be used to create a new class.

New class is known as derived class and the existing class is known as base class.

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Inheritance

Red Yellow

Orange

Blue

VioletGreen

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Polymorphism

Polymorphism allows the same function name to act differently in different classes.

It is an important feature in OOP concept and has the ability to take more than one form.

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Difference b/w C and C++

C C- Procedure Oriented

C does not have any classes or objects.

C input/output is based on library and the processes are carried out by including functions.

C functions do not support overloading.

C does not support new

or delete commands.

C++ Object Oriented

It supports Classes and Objects

C++ i/o is made through console commands cin and cout.

C++ supports Overloading.

New keyword is used to create an object for a class.

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C has a top down approach .

In c, declaring the global variable several times is allowed.

C has predefined data types.

c++ has a bottom up approach.

In C++, It is not allowed .

In c++,User can creates its own datatype using class.

Difference b/w C and C++(Contd…)

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Structure of a Program

// First Program#include <iostream.h> int main () {

cout << “Welcome to KGiSL!"; return 0;

}

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Structure of a Program(Contd…)

main()- The c++ program is a collection of functions.- Every program must have a main().

Comments- C++ introduces a new comment symbol //(double slash)

- Multiline comment/* line1 line2 line3 */

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Input and Output in C++

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Variables,Constants and Data types in C++

Variables- A variable is the storage location in memory that is stored by its value.

- A variable is identified or denoted by a variable name.

- The variable name is a sequence of one or more letters, digits or underscore, for example: character _

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Rules for defining variable name A variable name can have one or more letters or digits or

underscore for example character _.

White space, punctuation symbols or other characters are not permitted to denote variable name. .

A variable name must begin with a letter.

Variable names cannot be keywords or any reserved words of the C++ programming language.

C++ is a case-sensitive language. Variable names written in capital letters differ from variable names with the same name but written in small letters

. For example, the variable name ID differs from the variable

name id.

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Data types in C++

The most commonly used Data Types in C++ programming language:- short int - int - long int - float - double - long double - char

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Declaration of variable

The syntax for declaring variable name is:-datatype variable_name;

Example: int a;

If there exists more than one variable of the same type, such variables can be represented by separating variable names using comma.

For instance int x,y,z ;

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Operators in C++

The operators available in C++ programming language are:

Assignment Operator denoted by = Arithmetic operators denoted by +, -, *, /, % Compound assignment Operators denoted by +=, -=, *=, /=,

%=, >>=, <<=, &=, ^=, |= Increment and Decrement operator denoted by ++, -- Relational and equality operators denoted by ==, !=, >, <,

>=, <= Logical operators denoted by !, &&, || Conditional operator denoted by ? Comma operator denoted by ,

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Control Structures

Conditional Structures Iteration StructuresSelective Structure

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Conditional Structure

- It is also known as Decision Making Statements.- C++ has the following statements

if statement if…else statement Else if statement

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if statement:

syntax:if ( condition )

statement;

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Example for simple if

#include<iostream.h>

#include<conio.h>

void main()

{

int x=10,y=20;

if(x<y)

cout<<“x is less than y”;

getch();

}

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If….else statement

Syntax:

if ( condition ) { // Execute these statements if TRUE } else { // Execute these statements if FALSE }

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Example for if…else

#include<iostream.h>#include<conio.h>void main(){

int x,y;cout<<“Enter value of x:”;cin>>x;cout<<“Enter value of y:”;cin>>y;if(x>y){

cout<<“x is greater”;}else{

cout<<“y is greater”;}getch();

}

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if…else if statement:Syntax:

if(condition)

{

statement1;

}

else if(condition)

{

statement2;

}

else

{

statement;

}

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Example for else if statement


#include<conio.h>

void main()

{

int a,b,c;

cout<<“Enter value of a:”;

cin>>a;

cout<<“Enter value of b:”;

cin>>b;

cout<<“Enter value of c:”

cin>>c;

if(a>b && a>c){

cout<<“a is greater”;}else if(b>a && b>c){

cout<<“b is greater”;}else{

cout<<“c is greater”;}getch();}

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Iteration Structure

- A section of code in which an instruction or group of instructions is executed a specific number of times depending on the value of a loop counter.

for loop while loop do…while loop

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for loop

Syntax:

for (initialization; condition; increment/decrement){ statement; }

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Example of for loop

#include <iostream.h> int main() { int count; for(count=1; count <= 100; count=count++) cout << count << " "; return 0; }

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While loop

The while loop allows programs to repeat a statement or series of statements, over and over, as long as a certain test condition is true.

The while loop is an entry-condition loop. Syntax:

while (test_condition) {statement;

}

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Example


void main()

{

int num = 0; while (num < 10)

{

cout << "*";

num++;}

}

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Do…whileThe do-while loop is similar to the while loop, except that the test condition occurs at the end of the loop.

The do-while loop is an exit-condition loop. Syntaxdo{ statement; } while (condition);

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Example


#include<conio.h>

void main()

{

clrscr();

int num=0;

do

{

num++;

cout<<num;

}while(num<5);

getch();

}

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switch

- switch StatementIts objective is to check several possible constant values for an expression.

Syntax:switch (expression) { case 1: group of statements 1;

break; case 2: group of statements 2;

break;. default: default group of statements

}

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Example

#include <iostream.h>

#include<conio.h>

void main()

{

int color ;

clrscr();

cout<<“ Colors”;

cout<<“ ******”;

cout<<“1.Red 2.Green 3.Blue”;

cout<<"Enter an integer to choose a color:”;

cin>>color;

switch(color)

{

case 1:

cout<<"you chose red color\n";

break;

case 2:

cout<<"you chose green\n";

break;

case 3:

cout<<"you chose blue color”;

break;

default:

cout<<“Wrong choice";

}

getch();

}