1. Course Description: Title : Object Oriented Systems
Paper Code : CA - 205
Course : MCA
Faculty : Ms. Charu Sharma
Vikrant Gupta

2. Course Objectives & Prerequisites:
The course aims is to introduce the students to Object Oriented Programming Concepts with special emphasis on Object Oriented
Programming in C++.
The course begins with a gentle introduction to OOAD and OOP concepts. Students will then be presented with detailed discussion of Object Oriented Programming features in C++. At the end the use of few applications of OOAD and OOP concepts in areas like Software Engineering and Operating Systems.
In order to take the course the student should be familiar with Digital Computer System and must have completed a basic course in Computer Programming, preferably in C.  

3. Object Oriented Programming

4. Programming evolution
Machine code
● programs in binary code, executed directly by the processor
Assembly languages
● still low level programming, replaced machine code functions with mnemonics and memory addresses with symbolic labels
Procedural programming
● decompose programs into procedures/functions
Modular Programming
● decompose programs into modules
Object Oriented Programming
● decompose program into a set of objects
● objects interact with each other to form a system

5. What is OOP?
OOP is a design philosophy. It stands for Object Oriented Programming. Object-Oriented Programming (OOP) uses a different set of programming languages than old procedural programming languages (C, Pascal, etc.). Everything in OOP is grouped as self sustainable "objects“.

6. What is OOP?(Cont’d)
In order to clearly understand the object orientation, let’s take your “hand” as an example. The “hand” is a class. Your body has two objects of type hand, named left hand and right hand. Their main functions are controlled/ managed by a set of electrical signals sent through your shoulders (through an interface). So the shoulder is an interface which your body uses to interact with your hands. The hand is a well architected class. The hand is being re- used to create the left hand and the right hand by slightly changing the properties of it.

7. Problem Description
“ customers are allowed to have different types of bank accounts, deposit money, withdraw money and transfer money between accounts”

8. Procedural Approach
bool MakeDeposit(int accountNum,float amount); float Withdraw(int accountNum,float amount); struct Account { char *name; int accountNum; float balance; char accountType; };

9. Procedural Approach cont’d
Focus is on procedures
All data is shared: no protection
More difficult to modify
Hard to manage complexity

10. Procedural vs. Object-Oriented
Withdraw, deposit, transfer
Object Oriented
Customer, money, account

11. Mapping the world to software
Objects in the problem domain are mapped to objects in software
011101
10011
11101
11010
010101
10101

12. Object Oriented Account Data and operations are grouped together
Interface:
Set of available operations
Deposit
Withdrawl
Transfer

13. Object Oriented Paradigm
Provide flexible and powerful abstraction
Allow programmers to think in terms of the structure of the problem rather than in terms of the structure of the computer.
● Decompose the problem into a set of objects
● Objects interact with each other to solve the problem
● create new type of objects to model elements from the problem space
An object is an entity that:
● has a local state
● able perform some operation (behavior)

14. Object Oriented Paradigm(Cont’d)
It may be viewed as a combination of:
● data (attributes)
● procedural elements (methods)
Object Oriented Programming is a method of implementation where:
objects are fundamental building blocks
● each object is an instance of some type (class)
● classes are related to each others by inheritance

15. Fundamental concepts and properties
● object
● class
● method (message)
Properties:
● encapsulation
● inheritance
● polymorphism

16. Objects and Classes object class
Classes reflect concepts, objects reflect instances that embody those concepts.
object
class
girl
Jodie
Daria
Jane
Brittany

17. Objects and Classes (cont’d)
A class captures the common properties of the objects instantiated from it
A class characterizes the common behavior of all the objects that are its instances

18. Objects and Classes (cont’d)
Operations
MakeDesposit
Transfer
WithDraw
GetBalance
Class BankAccount
Balance
InterestYTD
Owner
Account_number
Balance 500
InterestYTD
Owner
Account_number
Balance 10,000
InterestYTD
Owner
Account_number

19. Objects as instances of Classes
The world conceptually consists of objects
Many objects can be said to be of the same type or class
My bank account, your bank account, Bill Gates’ bank account …
We call the object type a class

20. Instantiation An Object is instantiated from a Class
BankAccount myAccount;
myAccount = new BankAccount;

21. Objects and Classes Class Object Visible in source code
The code is not duplicated
Object
Own copy of data
Active in running program
Occupies memory
Has the set of operations given in the class

22. Classification Mammal Rodent Primate Cats Reptile Animal Squirel
Rabbit
Mouse

23. Classification Checking Account Value First Select Access
First Interest
Savings Account
Account

24. Encapsulation
Abstraction in OOP is closely related to a concept called encapsulation.
Data and the ways to get at that data are wrapped in a single package, a class. The only way to access such data is through that package. This idea translates to information hiding.

25. Encapsulation (Cont’d)
Encapsulation is the method of combining the data and functions inside a class. This hides the data from being accessed from outside a class directly, only through the functions inside the class is able to access the information.
This is also known as "Data Abstraction", as it gives a clear separation between properties of data type and the associated implementation details. There are two types, they are "function abstraction" and "data abstraction". Functions that can be used without knowing how its implemented is function abstraction. Data abstraction is using data without knowing how the data is stored.

26. Data Encapsulation class Account { public: float withdraw();
void deposit(float amount);
private:
float balance; );

27. Advantages of Encapsulation
Protection
Consistency
Allows change

28. Inheritance
A class which is a subtype of a more general class is said to be inherited from it.
The sub-class inherits the base class’ data members and member functions

29. Inheritance (Cont’d)
A sub-class has all data members of its base-class plus its own
A sub-class has all member functions of its base class (with changes) plus its own
Inheritance is meant to implement sub-typing (don’t abuse it)

30. Inheritance Examples

31. University community members
Employee
CommunityMember
Student
Faculty
Staff
Administrator
Teacher

32. Abstraction Management of complexity Hierarchical classification:
is-a relationship: inheritance
has-a relationship: containment

33. Abstraction Cont’d
One of the chief advantages of object-oriented programming is the idea that programmers can essentially focus on the “big picture” and ignore specific details regarding the inner-workings of an object. This concept is called abstraction.

34. Polymorphism One interface Multiple implementations Inheritance
Method overloading

35. Polymorphism (Cont’d)
Polymorphism describes how programmers write methods to do some general purpose function.
Different objects might perform polymorphic methods differently.

36. What is a good class ? A class abstracts objects
A class should be non-trivial in the context of the program (has data structures and operations different from other classes)

37. Motivation Procedural programming: Variables  objects Types  classes
Low-level, closer to hardware
More intuitive, less abstract
More ‘action’ oriented
Focus on ‘action’, ‘procedure’, ‘method’
Procedure-oriented
Object-oriented programming:
High-level
More abstract
Focus on ‘what to do’ not on ‘how to do’
In the implementation of OOP,
we still need sound ‘procedure programming’ skills!

38. Procedural programming: Object oriented programming:
A sequence of ‘procedures’ A sequence of ‘objects’!
int main() { int x,y,z; int a,b,c; a=f1(x); b=f2(y); c=f3(z); … } int f1() int f2() int f3()
int main() {
A a; B b; C c;
a.f1(); b.f2(); c.f3(); … }
Class A
Int x;
Int f1();
Class B
Int y;
Int f2()
Class C
Int z;
Int f3();

39. Object-oriented modeling and design

40. Introduction
It is a new way of thinking about problems using models based on real world concepts.
The basic construct is object which combines both data structure and behavior in a single entity.
Rambaugh presents an object oriented software development methodology, the Object Modeling Technique (OMT) which extends from analysis through design to implementation.

41. What is object-oriented?
Software is organized as a collection of discrete objects that incorporate both data structure and behavior.
In general it includes- identity, classification, polymorphism and inheritance.
Object Oriented Programming Language
= Object Based Programming Language(e.g. '83 Ada a Modula- 2,C++and Java,etc.)
+ Inheritance + Dynamic Binding

42. Identity
Identity means that data is organized into discrete, distinguishable entities called objects.
Objects can be concrete or conceptual.
In real world an object simply exist but within a programming language each object has a unique handle by which it can be uniquely referenced.
The handle can be implemented by address, array index or unique value of an attribute.

43. Classification
It means that objects with same data structure (attribute) and behavior (operations) are grouped into a class.
A class is an abstraction that describes important properties and ignores the rest.

44. Polymorphism
It means that the same operation (i.e. action or transformation that the object performs) may behave differently on different classes.
Specific implementation of an operation by a certain class is called a method.

45. Inheritance
It is the sharing of attributes and operations among classes based on a hierarchical relationship.
Subclasses can be formed from broadly defined class.
Each subclass incorporates or inherits all the properties of its super class and adds its own unique properties.

46. Object-Oriented Development?
The theme is the identification and organization of application concepts rather than final representation in a prog. Language.
OOD approach encourages software developers to work and think in terms of the application domain through most of the software engineering life cycle.
It is a conceptual process independent of a programming language until the final stage.

47. Object-Oriented Methodology
Stages.
Analysis
System design
Object design
Implementation

48. 3 Models
Object Model
Dynamic model
Functional model

49. Object Model
Describes basic structure of objects and their relationship.
Contains object diagram.
Object diagram is a graph whose nodes are object classes (Classes) and whose arcs are relationships among classes.

50. Dynamic model Describes the aspects of a system that change over time.
It specifies and implement control aspects of a system.
Contains state diagram.
State diagram is a graph whose nodes are states and whose arcs are data-flows.

51. Functional Model Describes data value transformation within a system.
Contains data flow diagram.
Data Flow Diagram is a graph whose nodes are processes and whose arcs are data flows.

52. Object-Oriented Concepts
Abstraction
Encapsulation
Combining data and behavior
Sharing
Object structure, not Procedure Structure
Synergy

53. On completion of the class, a student should be able:
To prepare object-oriented design for small/medium scale problems
To demonstrate the differences between traditional imperative design
and object-oriented design
To explain class structures as fundamental, modular building blocks
To understand the role of inheritance, polymorphism, dynamic binding
and generic structures in building reusable code
To write small/medium scale c++ programs with simple graphical user
interface
To use classes written by other programmers when constructing their systems

54. Summary
What is Object Oriented Programming? Object-oriented programming is a method of implementation in which programs are organized as cooperative collections of objects, each of which represents an instance of some class, and whose classes are all members of one or more hierarchy of classes united via inheritance relationships

55. Expected Result
100%