![C++
#include<iostream.h>
class Student
{ char name[25];
int rollno;
int ms1, ms2;
Public:
void read() {
cout>>”Enter name, roll no and marks in ms1, ms2n”;
cin>>name>>rollno>>ms1>>ms2; }
void display() {
cout<<name<<“ “ <<rollno<<“ “<<ms1<<“ “<< ms2;}
};
void main()
{
Student s1,s2;
s1.read();
s1.display();
s2.read()
s2.display();
}
JAVA
class Student
{ int rollno=10;
int ms1=28,ms2=18;
void m1()
{//instance area
System.out.println(rollno);
System.out.println(ms1);
System.out.println(ms2);
}
public static void main(String[]
args)
{
Student s= new Student();
System.out.println(s.rollno);
System.out.println(s.ms1);
System.out.println(s.ms2);
s.m1();
}
}
OOP is a bottom-up approach of Programming](https://image.slidesharecdn.com/2r-3ks03-oopunit-ipart-a2023-24-230821155858-2ea5d355/85/2R-3KS03-OOP_UNIT-I-Part-A-_2023-24-pptx-28-320.jpg)
![C++
class Hello
{ int i;
public:
{
int j;
void f1()
{
cin>>i;
cout<<"Hello!n";
cout<<i;
}
}
};
void main()
{
Hello h;
h.j=10;
h.f1();
}
Java
// Prints a value & message
public class Hello
{
int a=100;
public static void main(String[] args)
{
Hello o = new Hollo();
System.out.println(o.a);
System.out.println("Hello!n");
}
}
OOP is Bottom-Up Programming Approach.](https://image.slidesharecdn.com/2r-3ks03-oopunit-ipart-a2023-24-230821155858-2ea5d355/85/2R-3KS03-OOP_UNIT-I-Part-A-_2023-24-pptx-29-320.jpg)
![ It is a variable of type class.
C++
#include<iostream.h>
class Student
{ char name[25];
int rollno, ms1, ms2;
Public:
void read() {
cout>>”Enter name, roll no and marks in ms1, ms2n”;
cin>>name>>rollno>>ms1>>ms2;}
void display() {
cout<<name<<“ “ <<rollno<<“ “<<ms1<<“ “<< ms2; }
};
void main()
{ Student s1,s2;
s1.read();
s1.display();
s2.read()
s2.display();
}
It is a run time entity in OO Programs.
JAVA
public class Student
{ int rollno=10;
int ms1=28,ms2=18;
public static void main(String[] args)
{
Student s = new Student();
System.out.println(s.rollno);
System.out.println(s.ms1);
System.out.println(s.ms2);
s.m1();
}
void m1()
{
System.out.println(rollno);
System.out.println(ms1);
System.out.println(ms2);
}
}
• Just like we create variables of type integer i.e. int
a,b,c; Similarly, we can create variables of type
class, called Objects.](https://image.slidesharecdn.com/2r-3ks03-oopunit-ipart-a2023-24-230821155858-2ea5d355/85/2R-3KS03-OOP_UNIT-I-Part-A-_2023-24-pptx-54-320.jpg)
2R-3KS03-OOP_UNIT-I (Part-A)_2023-24.pptx
- 1. 3KS03 OBJECT ORIENTED PROGRAMMING Department of Computer Science and Engineering Shri Sant Gajanan Maharaj College of Engineering, Shegaon
- 2. Shri Sant Gajanan Maharaj
- 3. SELF INTRODUCTION • EDUCATION: B. E. (Computer Sci. & Engineering) M. E. (Computer Engineering) PhD (Pursuing in Computer Sci. & Engineering) • EXPERIENCE: o Industry Experience: 6 Month (S. L. Computers, Mumbai) o Teaching Experience: 27 Years ( SSGMCE, Shegaon) • Operation Research and Management (3U) • Programming Language (FORTRAN-77) (3U) • Application Software (3R) • Computer Oriented Operation Research (3R) • Visual Computing (3R) • Professional Ethics(3R) • SUBJECT TOUGHT: • Object Oriented Programming (C++) (2R, 2N) • Object Oriented Programming(Java)(2R) • Programming Methodology (Java) (2R) • Object Oriented Analysis and Design (4R) • Object Oriented System (M. E.) • Software Engineering (4R) • Data Structures (2R) • Network Security (4R) • System Security (M. E.) • Introduction to Cyber Security(3R) • Cryptography • System and Software Security • Discrete Structure • Theory of Computation • Database Management System (3R) Prof. V. S. Mahalle Area of Interest: Machine Learning, Deep Learning
- 4. “OBJECT ORIENTED PROGRAMMING” • Introduction & Importance of Subject: • Syllabus, Text books, Reference books…
- 5. Introduction and Importance of Subject • OBJECT ORIENTED: Programming Technique / Programming Approach • PROGRAMMING LANGUAGE: Solving problems using Computer, it requires Programming Language. Java: “Object Oriented Programming Language”. Demand of IT Industry to develop Applications. OBJECT ORIENTED PROGRAMMING
- 6. • Human to Human Communication: • We need a language to communicate with each others. We can use Marathi, Hindi, English …. What is Programming Language? • Human to Computer(M/C) Communication. • We need a language to communicate between Human & Machines. (M/C perform complex operations in easy way. We can use C, C++, Java … programming Language. “Communication is Possible because of Languages”. What is Language?
- 7. Classification of Programming Language: Programming Languages Machine Language Assembly Language High Level Languages • Low Level Language • Binary Language (0 & 1) • Translator: Not Required • Computer understand Lang. • Symbolic Language • Mnemonic Language • Symbols like: Load, Move, Add, Store … • Translator: Assembler • Just like English Language • BASIC, Pascal, FORTRAN, COBOL, C, C++, Java, Python, C#, PROLOG, .NET … • Translator: Compiler 00010001100100001001 00010011000110001111 00010010100… Executable Machine Code LOAD R1, b LOAD R2, h MUL R1, R2 <= Middle Level DIV R1, 2 L. Program RET Class demo { int rno; public: void read(); void display(); }
- 8. Advantages and Disadvantages: MACHINE LANGUAGE • Advantages: o It does not require any translator, It is directly understood by Computer. o It makes fast and efficient use of the computer. • Disadvantages: o Difficult to write and understand the code. o Program is written at h/w level, So Knowledge of hardware is necessary. ASSEMBLY LANGUAGE Advantage: o Writing programs in Assembly Language is easier & faster than writing program in Machine Language. • Disadvantage: o Difficult to write complex programs fastlly. o If program is too large then it is difficult to spot the errors. o Machine dependent, i.e. a Program written in one computer can not be run on another computer. HIGH LEVEL LANGUAGE • Advantage o Easy to understand the Programs. o Writing program in HLL is faster than writing program in Assembly Language. It is programmer friendly. • Disadvantage: o It takes additional translation time to translate it into machine code.
- 9. Classification of High Level Languages H.L. Programming Languages Procedure Oriented Programming Languages Object Oriented Programming Languages • These are two different approaches/ways for writing programs. for example: How you earn money? Different ways: -Doing Job -Doing Business -Taking Tution classes - Making videos on YouTube. Similarly, Writing programs in procedure oriented ways & writing programs in object oriented ways. . These are different ways or approaches to earn money. • Two different approaches of Program writing. • Two different ways to build programs • Two different program organization & development techniques. • Two different program writing styles.
- 10. Programming Languages: Procedure Oriented Programming Languages: • BASIC • Pascal • FORTRAN • C • C++ Object Oriented Programming Languages: • C++ • Java • Python • C# • VB.Net • PHP • When we write program in C, then we follow POP approach. • When we write program in Java, then we follow OOP approach. When we write program in C++, then we can follow POP or OOP approach. • That means • C is a Procedure Oriented Programming Language. • Java is a Object Oriented Programming Language. • C++ is both Procedure Oriented as well as Object Oriented Programming Language.
- 11. Language Name of Father (Inventors) C “Dennis Richie” American computer scientist C++ ” Bjarne stroustrup” is a Danish computer scientist, Java “James Gosling ” Canadian computer scientist Javascript ” Brendan Eich “ American technologist Ruby “Yukihiro Matz” Japanese computer scientist Father of Languages
- 12. JAVA : Most demanding programming language of IT Industries: JAVA : More popular programming Language:
- 14. JAVA: Most dominating programming language in variety of domains: Web Application Development: JavaScript Servlets, JSP Android Application Development Java Android Studio Enterprise Application Development J2EE Big Data Hadoop
- 15. Unit-I Introduction to Object Oriented Programming: • Introduction, Need of OOP • Principles of OOP Languages • Procedural Language Vs OOP • Application of OOP Java Virtual Machine(JVM) Java Features, Program Structure. Java Programming Constructs: •Variables, Primitive data types, Identifier, Literals •Operators, Expressions, Precedence Rules and Associativity •Primitive Type Conversion and Casting, •Flow of Control Syllabus
- 16. Unit-II Classes and Objects: • Classes, Objects, Creating Objects • Methods, Constructors, Cleaning up Unused Objects • Class Variable and Methods • this keyword • Arrays • Command Line Arguments
- 17. Unit-III Inheritance: • Inheritance vs. Aggregation • Method Overriding • super keyword, final keyword • Abstract class Interfaces, Packages and Enumeration: • Interface • Packages, java.lang package • Enum type
- 18. Unit-IV Exception: • Introduction • Exception handling techniques • User-defined exception • Exception Encapsulation and Enrichment Input/Output: • The java.io file class • Reading and Writing data • Randomly Accessing a file • Reading and Writing files using I/O package.
- 19. Unit-V Applets: • Introduction, Applet class, Applet structure, Applet Life cycle. • Common Methods used in displaying the output: paint(), update() and repaint(). • More about applet tag, get Document Base() and get Code Base() methods. • Applet Context Interface, Audio clip. • Graphic class, Color, Font, Font Metrics.
- 20. Unit-VI Event Handling: • Introduction • Event delegation Model • Java.awt.event • Sources of events, • Event Listeners, • Adapter classes • Inner classes. Abstract Window Toolkit: • Introduction • Components and Containers • Button, Label, Checkbox, Radio Buttons, List Boxes, Choice Boxes, Textfield and Textarea • Container class • Layouts • Menu, Scrollbar.
- 21. Text Books: 1. Sachin Malhotra and Saurabh Choudhary: Programming in Java, Oxford University Press 2010. 2. Herbert Schildt: Java Complete References (McGraw Hill) Reference Books: 1. H. M. Dietel and P. J. Dietel, “ Java How to Program” Pearson Education 2. E. Balagurusamy: Programming with Java (McGraw Hill) 3. Dr. R. K. NageswaraRao: Core Java An Integrated Approach (Dreamtech) 4. Khalid Mughal: A Programmer’s Guide to Java Certification, 3rd Edition (Pearson) 5. Sharnam Shah and Vaishali Shah: Core Java for Beginners,(SPD),2010.
- 22. Unit-I Introduction to Object Oriented Programming: • Introduction, Need of OOP • Principles of OOP Languages • Procedural Language Vs OOP • Application of OOP Java Virtual Machine(JVM) Java Features, Program Structure. Java Programming Constructs: •Variables, Primitive data types, Identifier, Literals •Operators, Expressions, Precedence Rules and Associativity •Primitive Type Conversion and Casting, •Flow of Control
- 23. 1. Introduction to Object Oriented Programming 2. Need of OOP Objectives
- 24. • Procedure Oriented and Object Oriented are programming approaches/Paradigms of Programming. ways to build programs two different program organization & development techniques program writing styles. 1. Introduction to Object OrientedProgramming
- 25. What is Procedure Oriented Programming Approach? • Writing list of sequence of statements/Instructions for computer to follow to solve a particular problem. OR • In Procedural Language, A program is a list of sequence of statement/instruction for computer to execute. Computer execute statements one after another. Example 1: To withdraw money from ATM. To solve this problem, we use following sequence of steps. (i) Insert ATM card in ATM m/c. (ii) Enter Pin Number. (iii) Enter amount to withdraw. (iv) Collect money and ATM card. (v) end We required to follow certain procedure. From top to bottom. When we want, Computer execute statements sequentially, then we apply POP approach.
- 26. Example 2: Write a program to read test marks of two subjects of a student and find the average marks. C #include<stdio.h> void main() { int ms1, ms2, total, avg; printf(“Enter marks in test1 and test2n”); Scanf(“%d %d”, &ms1, &ms2); total = ms1+ms2; avg = total/2; printf(“%d Average=”, avg); } C++ #include<iostream.h> void main() { int ms1, ms2, total, avg; cout<<“Enter marks in test1 and test2n”; cin>>ms1>>ms2; total = ms1+ms2; avg = total/2; cout<<“Average=”<<avg; } POP is a top-down approach of Programming C & C++ Programs written using POP approach.
- 27. What is object oriented programming approach? • OOP is different programming approach than POP approach. • It is a new way of (i) decomposition of problem (ii) Writing programming solutions. • OOP approach, which deals with the concept of objects to build programs/ application software. • In OOP, we organize software/program as a collection of objects & that work together concurrently to produce software. Black Board Teacher Chalk Chair Object Object Object • Object is the heart of Object Oriented Programming. • Object is the major & most important entity in object oriented programs. They interact with each others by sending messages. Object
- 28. C++ #include<iostream.h> class Student { char name[25]; int rollno; int ms1, ms2; Public: void read() { cout>>”Enter name, roll no and marks in ms1, ms2n”; cin>>name>>rollno>>ms1>>ms2; } void display() { cout<<name<<“ “ <<rollno<<“ “<<ms1<<“ “<< ms2;} }; void main() { Student s1,s2; s1.read(); s1.display(); s2.read() s2.display(); } JAVA class Student { int rollno=10; int ms1=28,ms2=18; void m1() {//instance area System.out.println(rollno); System.out.println(ms1); System.out.println(ms2); } public static void main(String[] args) { Student s= new Student(); System.out.println(s.rollno); System.out.println(s.ms1); System.out.println(s.ms2); s.m1(); } } OOP is a bottom-up approach of Programming
- 29. C++ class Hello { int i; public: { int j; void f1() { cin>>i; cout<<"Hello!n"; cout<<i; } } }; void main() { Hello h; h.j=10; h.f1(); } Java // Prints a value & message public class Hello { int a=100; public static void main(String[] args) { Hello o = new Hollo(); System.out.println(o.a); System.out.println("Hello!n"); } } OOP is Bottom-Up Programming Approach.
- 30. Real Life Example Procedure Oriented Approach • To withdraw money from ATM. To solve this problem, we use following sequence of steps. (i) Insert ATM card in ATM m/c. (ii) Enter Pin Number. (iii) Enter amount to withdraw. (iv) Collect money and ATM card. (v) End. Object Oriented Approach
- 31. 2. Needof Object OrientedProgramming Why Object Oriented Programming approach was developed? (I) To overcome limitations in earlier approach. (II) OOP approach have number advantages. (III)OOP have best programming concepts & several powerful features that very closely maps with real world examples.
- 32. (I) To overcome difficulties & limitations in earlier POP approach. • Writing program using Procedure Oriented approach and When length of program increases, then its complexity also increases. So (i) it is very difficult to maintain a very large program in earlier POP approach. This problem is overcome by dividing large program into different functions, but it gives birth to other problems. (ii) Functions have unrestricted access to global data. (iii) They provide poor mapping to real world entities. • Other Problems: (iv) More importance given to procedure/algorithms rather than data. (v) Data is not secure, it moves openly from function to function.
- 33. Concepts and features of OOPs closely maps with real world entities. • Features or characteristics of OOP: (i) More importance is given to data rather than procedure. (ii) Programs are divided into objects (iii)Data is hidden and can not be accessed by external functions. (iv) New functions and data can easily be added whenever needed. (v) Follow bottom-up approach in program design.
- 34. (II) Benefits/Advantages of Object Oriented Programming Approach: • Faster Development of Software. • Adapt to changing requirements • Reusability: reuse existing code to extend functionality of software. • Easier to maintain • Increased software quality.
- 35. (III) OOP have best programming concepts & several powerful features that very closely maps with real world examples. Object Oriented Programming Concepts & Features 1. Object 2. Classes 3. Encapsulation 4. Abstraction 5. Inheritance 6. Polymorphism
- 36. 1. What is Object Orientated/Orientation? OR What is Procedure Oriented Programming Approach? AND What is Object Oriented Programming Approach?
- 37. 2. Why Object Orientated Programming Approach was developed? 3. What are the different characteristics/features of o Procedure Oriented programming approach and o Object Orientated Programming Approach?
- 38. o Some Characteristics exhibited by Procedure Oriented Programming are: • Emphasis is on doing things (Algorithms). • Large programs are divided into smaller programs known as functions. • Most of the functions share global data. • Data move openly around the system from function to function. • Employ top-down approach in program design.
- 40. o Some Characteristics exhibited by Object Oriented Programming are: • Emphasis is on data rather than procedure. • Programs are divided into what are known as Objects. • Functions that operate on the data of an object are tied together in the data structure. • Data is hidden and cannot be accessed by external functions. • Objects may communicate with each other through functions. • New data and functions can be easily added whenever necessary. • Follows bottom-up approach in program design.
- 42. 1. Principles of OOP LANGUAGES. 2. Procedural Languages Vs OOP Languages 3. Applications of OOP
- 43. 3. Principles of Object Oriented Programming 4. Procedural Languages Vs OOP Languages 5. Applications of OOPs Objectives
- 44. 3. Principles of OOP Languages • OOP languages ==> follow certain principles. • It has ==> Some new best programming concepts & several powerful features. Language that has this concepts & features, then that Language is called Object Oriented Programming Language. Different OOP concepts & features: 1.Classes 2.Objects 3.Encapsulation 4.Abstraction 5.Inheritance 6.Polymorphism OOP concepts & features are widely used in almost all modern programming Languages except C. Pillars of any OOP Language. If you want to start programming in C++, Java or Python, then you must understand the concepts & features of OOPs as these languages are Object Oriented Programming Languages.
- 45. • Class is the description of similar type of objects. • Abstract things are called class and they do not have any physical existence. • Class is a logical entity which contains logic of an application. • Class is a blue print, it decide object creation and without class, there is no object. Class is not a real world entity. It is just a template or blueprint or prototype from which objects are created) • Based on single blueprint multiple objects are possible. • Class is a user defined datatype and it contains attributes (data members) & 1. Classes:
- 46. What is class? Class is a description of similar type of Objects. ANIMALS FURNITURE FRUITS • Class is a description of similar objects, that shares common attributes & behaviors. Student name class rollno read() display() Class Diagram
- 47. • Example: • Teacher: Dr. P. K. Bharne, Prof. J. M. Patil, Prof. Ms. K. P. Sable… • Animal: • Classes Dog, Cat, Cow, Tiger… • Furniture: Chair, Table, Black Board… • Vehicle: Car, Bus, Train, Boat, Plane… • Objects • Q Chair, Table, Black Board… belongs to which class? Ans: It belongs to Furniture class • Q Dog, Cat, Cow… belongs to which class? Ans: It belongs to Animal class We can not say, it belongs to Vehicle Abstract Things are called ==> Classes. Specific or Concrete things are called ==> Objects. Specific Things Abstract Things
- 48. • Suppose, I ask you, call to teacher. then you will confuse ==> Which teacher? Teacher is there, but something is hidden & you do not guess. • Suppose, I ask, show me a Animal ==> confuse, which Animal? Teacher, Animal, Furniture … ===> They do not have any Physical existence. Classes are logical in nature and they do not have any existence. Example: Furniture do not have any existence but Chair, table… do exist. Class is a description of similar type of objects. Example: Furniture: Chair, table, black board… Animal: dog, cat, cow… We can not say ‘Tiger’ is a Furniture.
- 49. A Class can also defined as the blue print for an Objects. Or A class serves as template for Object Once class is defined, then we can create any number of objects of that class. A Class is defined as a user defined data type. int, float, char …. ===> Predefined data types Int a, b, c; ==> a, b, c of type int Fruit, Animal, Shape… ==> classes Fruit mango, orange, apple; ===> mango, orange, apple of type Fruit. (User defined). A Class contains two things: Data members & Methods Once class is defined, then we can create any number of objects of that class.
- 50. • Graphical Notation for Class: • Example===> Name Compartment (Mandatory) Attribute Compartment (Optional) Operation Compartment (Optional) BankAccount - accountNumber : string - owner: string - Balance: double = 0.0 + deposite( amount: double) + withdraw (amount: double) + getOwner() : string + getBalance(): double name compartment attribute compartment operation compartment class name initial values visibility adornment Naming Convention: Class Name: Write in UpperCamelCase. Attributes & Operations: Write in LowerCamelCase Visibility Adornment • Highlight imp features, clarity & readability dig. + : public - : private # : Protected • Graphical Notations of Class called Class Diagram.
- 51. • Identify classes from following and then corresponding objects? Vehicle, dog, bus, peckok, circle, cat, sham, Bird, Animal, Shape, car, ram, parrot, Student, square Classes Objects Vehicle car, bus Bird parrot, peckok Animal cat, dog Shape circle, square Student ram, sham
- 52. Concrete/Specific thing is called ===> Object . Object is a real world entity & they have physical existence. . 2. Objects :
- 53. It is a discrete & distinguishable entity with a well-defined boundary that encapsulate states and behaviors. Maker Model Color Year Price Start() Drive() Park() car Breed Color Height Weight Yearofbirth Eating() Sleeping() dog Task Performed
- 54. It is a variable of type class. C++ #include<iostream.h> class Student { char name[25]; int rollno, ms1, ms2; Public: void read() { cout>>”Enter name, roll no and marks in ms1, ms2n”; cin>>name>>rollno>>ms1>>ms2;} void display() { cout<<name<<“ “ <<rollno<<“ “<<ms1<<“ “<< ms2; } }; void main() { Student s1,s2; s1.read(); s1.display(); s2.read() s2.display(); } It is a run time entity in OO Programs. JAVA public class Student { int rollno=10; int ms1=28,ms2=18; public static void main(String[] args) { Student s = new Student(); System.out.println(s.rollno); System.out.println(s.ms1); System.out.println(s.ms2); s.m1(); } void m1() { System.out.println(rollno); System.out.println(ms1); System.out.println(ms2); } } • Just like we create variables of type integer i.e. int a,b,c; Similarly, we can create variables of type class, called Objects.
- 55. ANIMALS Class is a collection of similar types of Objects. Object-1 (Cat) Object O1 Object-3 (Horse) Cat is an instance of class ANIMAL Each Object is an Instance of a Class. Breed Height Weight Object O2 Breed Height Weight O1 O2 Object is an Instance of a Class. Each Object takes its own space in Memory. Object-2 (Dog)
- 56. • Characteristics of Objects: All Objects have three characteristics: (i) Identity (ii) State (iii) Behavior
- 57. (ii) State: • It is determined by attribute value. Example: If balance = -ve, then state = “Overdrawn” If balance = 0, then state = “Empty” If balance = +ve, then state = “In-credit” • May change over time (iii) Behavior: The set of operations that an object can perform. (i) Identity: • Each object must have its own unique name. This property, distinguishes objects from one-another.
- 58. Example#1: Attributes of the Object Behaviors of the Object States of the Object Attribute Value of Attribute Name Hoda City ZX Car Starts - StartCar() Car is Moving - Moving State Car Company Honda Car Stops - StopCar() Car us in Stop state - Stop State Car Owner Ranjeet Deshmukh Change the speed - Accelerate() Car Number MH-09 BD 4928 Car Color White Tank Capacity 35 Liters Seating Capacity 5 Mileage 12 Km/Lit Car
- 59. Example#2: myBankAccount Attributes of the Object Behaviors of the Object States of the Object Attribute Value of Attribute Owner Name V. S. Mahalle Withdraw() incredit Account Number 1234567 Deposite() empty Date of Opening 20 Dec. 1994 Overdrawn Current Balance 10 Lac Attributes of the Object Behaviors of the Object States of the Object Attribute Value of Attribute Name Deepika - speak() talking Sate Birthdate 15 Aug. 1982 - walk() walking State Address Nariman Point, Bombay - run() running State Education MBA - dance() dancing State Example#3:
- 60. Messaging • In OO systems, Object interact with each others by sending messages. • Objects send messages to each other over links. • These messages cause an object to invoke an operation 60 Account object responds by invoking its withdraw operation. This operation decrements the account balance by 150.00. Bank Object Account Object withdraw( 150.00 ) Bank object sends message “withdraw 150.00” to an Account object. message
- 61. • Graphical Notation of Objects/(Syntax): always underline OBJECT IDENTIFIER Name Compartment Attribute Compartment • Object Identifier: It consist of any of the following: (i) Class name alone: (ii) Object Name alone: (iii) Object Name concatenated with class name: :Account sachinAccount sachinAccount:Account • Attribute Syntax: VM attribute name: attribute type = Value • Naming: object and attribute names Write in lowerCamelCase
- 62. Example of Object: 62 sachinAccount : Account accountNumber : String = "1234567" owner : String = “Sachin" balance : double = 300.00 attribute name attribute compartment name compartment attribute type attribute value object name class name sachinAccount : Account sachinAccount : Account object and class name object name only class name only an anonymous object object identifier (must be underlined) • Attribute compartment is omitted to simplify the diagram
- 63. Classes Objects Class is not real world entity & they do not have any physical existence. Object is a real world entity & they have physical existence. Abstract things are called class. Ex.-Furniture, Student, Animal Concrete/Specific things are called objects. Ex.- chair, table, anil, sunil, apple, orange… Class is a logical entity, which contains logic of application. Object is a physical entity, which represent memory. Class is a blue print for an object. Object creation is not possible without class. Class is a user defined data type. Object is an instance of a class. It is a run time entity in OO programs
- 64. 3. DataEncapsulation • The wrapping up (binding) of data and methods(functions) that operate on it into a single unit(class) is termed as data encapsulation. * Capsule in medical term class Demo { variables data member + methods(behavior) member methods } Medicine is kept inside Capsule. Why? ==>To protect it from outside environment (moisture, temperature, dust…). • Cap is termed as a class in Object Oriented terminology & to keep data secure, we place it in the class. (i) Data & functionality binding together within a class. (ii) Access to data in controlled manner. Two things Encapsulation have:=>
- 65. Data hiding: Encapsulation is as a protective wrapper, that prevent the data & methods from accessing by other methods defined outside the class. Private public Data method method m e t h O d • Generally, Data Members ==> Declared as Private Member methods ==> Declared as Public Private: Restricted access from outside class. Public: Can access anywhere through class Object. Private data members in class are hidden and not accessible to methods defined outside of a class. It is accessible only through its public member methods. This process or mechanism is called as data hiding. method
- 66. • Example1: When will you come to Shegaon, bring home made sweet for me. 4. Data Abstraction Example2: Driving a Car • We are happy with the abstraction provided to us like steering, brakes, gear etc. • We interact with them without knowing the internal details about: how the car engine works and how the car stops on applying brakes.(We don’t want to know this) Highlighting only the essential features and hiding unnecessary details. That reduces the complexity & increases the efficiency. • Displaying only the useful information & hiding unnecessary details from the users.
- 67. • We follow the instruction given by GUI. We do not know the necessary technology back site of it, we are not interested. • When we enter pin, we are not interested what is happen internally, which code is executed, where it is executed. • We are also not interested to know all the things in detail. • Simply we are using the ATM by following the Instructions. • Advantage: 1. Hiding is there, the biggest advantage is Security. 2. Maintainability of application is improve. Encapsulation: => Hiding data. Abstraction:=> Hiding implementation details. Implementation of abstraction in Java by: abstract class Interface Example3: ATM Highlighting set of services they are offering and hiding internal implementation.
- 68. • Relationship between classes • Organization of classes into Super-Subclass hierarchy. • Sharing of class members (attributes and methods) among classes based on hierarchical relationship. • Deriving a new class from existing class is called Inheritance. • Base/Super/Parent class • Derived/Sub/Child class • 5. INHERITANCE Class D Class B Parent Child Vehicle Car MotorCycle Common features of classes are defined into Super class. Each sub-class inherits, all the features of its super class & can add its own features. • Inheritance increases the reusability of code. • Inheritance increases the readability of code.
- 69. “IS A” Relationship: • How can we find there is an Inheritance or not? • Inheritance is one sided. One Direction it is right. Other Direction it is wrong. • Father gives his property to child , so child is the taker and father is giver. • child couldn’t give its property to father so Inheritance is one sided • Examples: • Faculty is a Person. • Student is a Person. • Apple is a Fruit. • Dog is a Animal • Chair is Furniture. • A car is a Vehicle. There is “is a” relationship between Classes. & We are able to relate two classes, then there is a Inheritance relationship. extends keyword is used to implement Inheritance in Java.
- 70. Types of Inheritance: 1. Single Inheritance 2. Multilevel Inheritance 3. Multiple Inheritance 4. Hierarchical Inheritance 5. Hybrid Inheritance Class A Class B Class A Class B Class C Class B2 Class B1 Class C Class A Class B1 Class B2 Class B1 Class B1
- 71. 6. polymorphism Poly = Many and Morphism = Forms. Polymorphism = Many forms. It can be defined as the same thing being used in different forms. • Example: Student (If your are in class room that time you behave like a student) • Yourself Customer (When you are in market at that time you behave like a customer) Son/Daughter (When your at your home at that time you behave like a son/daughter) • Here one person presents different-different behaviours. • More than one behaviours(Methods) with same name is called Polymorphism. • In Java, add two integers int a = 10, b = 20,c; • + c = a + b; concatenate two strings. System.out.println(“c=”+c);
- 72. Addition add(int i, int j); add( float a, float b) Types of Polymorphism: Polymorphism 1. Compile Time Polymorphism 2. Run Time Polymorphism or or Static Polymorphism / Early Binding. Dynamic Polymorphism / Late Binding *Memory allocated only at Compile time. *Memory allocated at Run time. Example of Compile time polymorphism is Method Overloading Example of Run time polymorphism is Method Overriding Shape area() appropriate method is invoked at compile time by matching number, order & type of arguments Method name -> Same Signature-> Different Method name -> Same Signature-> Same appropriate method is invoked at run time by matching with reference object. Circle area() Rectangle area()
- 73. 4. PROCEDURAL LANGUAGE VS OOP Difference Between Procedural and Object Oriented Programming Languages Procedural Language OOP 1. Separate data from functions that operate on them. 1. Encapsulate data and methods in a class. 2. Not suitable for defining abstract types. 2. Suitable for defining abstract types. 3 Debugging is difficult. 3. Debugging is easier. 4. Difficult to implement change. 4. Easier to manage and implement change. 5. Not suitable for larger programs/applications. 5. Suitable for larger programs and applications. 6. Analysis and design not so easy. 6. Analysis and design made easier. 7. Faster. 7. Slower. 8. Less flexible. 8. Highly flexible. 9. Data and Procedure based. 9. Object oriented.
- 74. Procedural Language OOP 10. Less reusable. 10. More reusable. 11. Only data and procedures are there. 11. Inheritance, encapsulation and polymorphism are the key features. 12. Use top-down approach. 12. Use bottom-up approach. 13. Only a function call to another. 13. Object communication is there. 14. Example: Basic, FORTRAN, Pascal, C. 14. Example: C++, JAVA, Python,VB.NET, C#.NET 15. Does not have access specifiers/modifiers. 15. Use public, private, protected access specifiers/modifiers. 16. Overloading is not possible. 16. Supports Method Overloading. 17. Less secure. (Data hiding is not possible) 17 Highly secure. (Data hiding is possible) 18. More emphasis is given to Procedure/Algorithm. 18. More emphasis is given to data.
- 75. 5. APPLICATIONOF OOP Y2K Problem: Occurs due to the use of Procedural software development approach. Occurs due to the writing convention of year attribute. Programmer consider only two digits in year instead of four digits, when they specify system date during implementation of software. Because of consideration of two digits in year, all the computer in the world suddenly stops their working on 31st December 99 at 12’O clock midnight. (After year 98, it change to 99 but after 31st Dec. 99, year change to 2000). Conversion of year in date, from 2 digit to 4-digit is not any easy task, when we use Procedural Software Development Approach. It requires to analyze & make changes in multiple lines of code. But when Object Oriented Software Development Approach is used, then change is made only in class and that change is automatically reflected in all objects. i.e. It easier to over come any problem when OO software development approach is used. (There is no need to make changed in whole system.
- 76. The applications of OOP, where Object Oriented Programming is suitable: 1. Real time system: What is a real time system? It is a system where the parameters change every time. Thus, output changes instantaneously. It results in a dynamic system. So we can say run time system is a dynamic system. For example: A Thermal Plants: temperature, water level & other parameters changes frequently, so it is a dynamic system. OOPs is used to develop such a system. 2. Simulation and modeling: What is a Simulation? Simulation means imitation of real world product. Without physical construction, we can develop a product & we can check how its looks like. For example: A Car Industry, initially they develop a simulation & modeling system instead of directly going to develop a real product. This can easily be represented using OOP. 06 OOPS Benefits & Applications: 1341_004_KMM
- 77. 3. CAM/CAD Systems: Computer Aided Manufacturing Computer Aided Design Here also we can make use of OOP. 4. Office Automation System: Automation is a type of real system Embedded systems makes it easy Here also we make use of OOP to develop automation & embedded systems. 5. AI (Artificial Intelligence): (Combination of both hypermedia and real time system) 6. Neural Network and Parallel Programming: Refer to a network of biological neurons Consists of artificial neurons or nodes Large problems divided into smaller ones; solved concurrently (in parallel)