1 cis601: object-oriented programming in c++ note: cis 601 notes were originally developed by h. zhu...
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CIS601: Object-Oriented Programming in C++
Note: CIS 601 notes were originally developed by H. Zhu for NJIT DL Program. The notes were subsequently revised by M. Deek.
Lesson #1
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Goals for the Course
To understand Object Oriented programming
To further develop your C++ skills
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Course Coverage Fundamentals of object-oriented
programming*Data abstraction
*Encapsulation
*Inheritance
*Dynamic binding
*Polymorphism
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C++ will be used as a vehicle to illustrate and implement OOP concepts.
Object-oriented paradigm will be applied to design and programming.
Course Coverage cont.
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Effects of OO methodology on software design maintenance extensibility reusability
Course Coverage cont.
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Prerequisites Working knowledge of
C/C++ Familiarity with operating systems Familiarity with compilers
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Lectures 1. Introduction to Object-Oriented
Programming 2. Overview of basic structures of C++ 3. Objects and Classes 4. Objects and Classes in C++ 5. Inheritance 6. Inheritance in C++ 7. Polymorphism and That in C++
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Lectures cont.
8. Operator Overloading in C++ 9. Templates and Friends in C++ 10. I/O Streams in C++ 11. Exception Handling in C++ 12. Container Classes in C++ 13. Object-Oriented Analysis and Design 14. Case Studies and Review
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Thinking Methodology
Induction From specialization to generalization
to create the word “dog” from different dogs
Dog
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Thinking Methodology
Deduction(infer) From generalization to specialization
From the word “dog” you have learned that an animal is or is not a dog.
DOG
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Design Methodologies
Functional decomposition (Top-Down) The whole system is characterized by a
single function, and then the function is decomposed into a set of functions in a process of stepwise refinement.
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Functional decomposition
The System
Function1 Function2 Function3
Function11 Function12
. . . . . .
. . . . . .
. . . . . .
Studying
Desk Table top Filing cabinet Bookshelves
Left drawer Middle drawer Right drawer
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Design Methodologies Functional composition (bottom-up)
To create different components of a function from a library of functions.
To integrate components into a module and form a more significant function.
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Functional composition
The System
Function1 Function2 Function3
Function11 Function12
. . . . . .
. . . . . .
. . . . . .
Studying
Desk Table top Filing cabinet Bookshelves
Left drawer Middle drawer Right drawer
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Functional (De)Composition
Modules with well-defined semantics that can be directly implemented.
Procedures own the data. Data plays a secondary role. Does not necessarily reflect the
states of abstraction in the application.
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Object-Orientation
A thinking methodology Everything is an object. Any system is composed of objects (a system
is also an object). The evolution and development of a system i
s caused by the interactions of the objects inside/outside a system.
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Everything is an object
A student, a professor A desk, a chair, a classroom, a building A university, a city, a country The world, the universe A subject such as CS, IS, Math, History, …
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Systems are composed of objects
An educational system An economic system An information system A computer system
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The development of a system is caused by interactions
NJIT is defined by the interactions among: students professors staff Board governance State governance … ...
Inside NJIT
Outside NJIT
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Design Methodologies Object-Orientation is a design
methodology(OOA/OOD) Objects are the building blocks of a
program (interface, editor, menu, file, etc.); data managing object (db), etc.)
Objects represent real-world abstractions within an application.
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Design Methodologies
Object-orientation supports induction: objects -> a class
This needs tools and deduction: a class ->objects
This needs programmers
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Design Methodologies
Object-orientation supports Top-down: from a super-class to sub-
classes Bottom-up: from sub-classes to a sup
er-class
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Programming Techniques
The evolution of programming techniques is to make languages more expressive to control complex systems more
easily
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Abstract Data Types(ADTs)
Abstraction Properties Abstract Data Types and Object-
Orientation
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Abstraction
to understand a problem by separating necessary from unnecessary details
To define the interface to a data abstraction without specifying implementation detail.
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Problem
Model
Abstraction
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Properties of ADT With abstraction, you create a well-
defined entity These entities define the data
structure as a set of items. For example, each employee has a name,
date of birth, and social number...
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Properties of ADT(Cont.)
The data structure can only be accessed with defined operations. This set of operations is called the interface
An entity with these properties is called an abstract data type (ADT).
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Interface
Operations
Abstract Data Structure
Abstract Data Type
ADT
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Definition (ADT)
ADT is characterized by the following properties: 1. It exports a type. 2. It exports a set of operations. 3. Operations of the interface are the only
access mechanism to the data structure. 4. Axioms and preconditions define the
application domain of the type.
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Example: ADT List
Type List. The interface to instances of type List is
defined by the interface definition file. Operations: insert, get, append, delete,
search,…
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List The application domain is defined by the s
emantical meaning of the provided operations. Axioms and preconditions include statements such as ``An empty list is a list.'' ``Let l=(d1, d2, d3, ..., dN) be a list. Then l.app
end(dM) results in l=(d1, d2, d3, ..., dN, dM).'' ``an element of a list can only be deleted if the l
ist is not empty.''
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Encapsulation
Combines the data and the operations Encloses both variables and functions Keeps details of data and operations
from the users of the ADT
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Encapsulation (cont.)
Allows for modularity Controls access to data Separates implementation from
interface Extends the built-in types
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Object-Oriented Programming
Objects are derived from ADTs. Interacting objects handle their own ho
use-keeping. Objects in a program interact by sendin
g messages to each other.
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Object1
Data1+Procedures1
Data Data1 Object3
Data3 + Procedures3
Object2
Data2 + Procedures2
Object4
Data4 + Procedures4
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Object-Oriented Programming
Each object is responsible to initialize and destroy itself.
Therefore, there is no need to explicitly call a creation or termination procedure.
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ADT and Object-Orientation
ADTs allow for the creation of instances with well-defined properties and behavior.
In object-orientation, ADTs are referred to as classes.
Therefore, a class defines the properties of objects called instances.
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ADT and Object-Orientation
ADTs define functionality by emphasizing the involved data, their structure, operations, axioms and preconditions.
Object-oriented programming is ``programming with ADTs'': combining functionality of different ADTs to solve a problem.
Therefore, instances (objects) of ADTs (classes) are dynamically created, destroyed and used.
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Inheritance(Hierarchy)
Expresses commonality among objects Allows code reusability Highlights Generalization/Specialization
relationships
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Polymorphism
The ability of objects to respond differently to the same message or function call.
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Modules Information hiding Data encapsulation Abstract data types Objects
Object-Orientation Evolution
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Remember: Encapsulation (Data & Operations)-- A
technique for Information Hiding. The users of the objects do not need to know the details of the data and operations of the objects.
Data Abstraction -- the procedure to define a class from objects.
Abstract Data Type-- Class.
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Object view Makes systems more understandable Unifies design and programming
methods Initial program thoughts are informal
objects-and-interactions, even when using non-OO languages.
Objects and Large Software Systems
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Objects and Large Software Systems
Divides code into logical chunks Allows for "off-the-shelf" code libraries
to be reused Supports code evolution: internals can
always be re-written as long as interface stays the same
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Reading
Chapter 1 Sections 1.1-1.2 Chapter 5 Sections 5.1-5.2