Object Oriented Programing JAVA presentaion
- 1. Welcome Presentation To: Md. Reduanul Haque Lecturer of CSE Daffodil International University
- 2. Presentation About Object - Oriented Programming Concepts
- 3. Group Members Pritom Chaki ID: 151-15-453 Nur E Nahain Shanto ID:151-15-245 Kumol Khanto Bhoumik ID:151-15-254 Mokabbir Alam Sani ID: 151-15-240
- 4. Topics Fundamental of OOP Encapsulation Inheritance Abstract Class Association Polymorphism Interface Exceptional Handling
- 5. Fundamental of OOP To know the Object Oriented Programming we should know two things: Object Class
- 6. Object Objects are key to understanding object-oriented technology Definition: An object is a bundle of variables and related methods. An object has two property: 1. Has property 2. Does Property
- 7. Example: For Tourist Guide App: Has Property: Tourists, Places, Transports, Hotel; Does Property: Search for Places, Login, Search or Booking Transport and Hotel
- 8. Class Software “blueprints” for objects are called classes Definition: A class is a blueprint or prototype that defines the variables and methods common to all objects of a certain kind Each object has a class which defines its data(Has property) and behavior(Does property).
- 9. Encapsulation Encapsulation is the mechanism that binds the data & function in one form known as class. The data & function may be private or public. Data fields are private. Constructors and assessors are defined (getters and setters).
- 10. Example
- 11. Encapsulation Cont…. Ensures that structural changes remain local: Changing the class internals does not affect any code outside of the class Changing methods' implementation does not reflect the clients using them Encapsulation allows adding some logic when accessing client's data Hiding implementation details reduces complexity easier maintenance
- 12. Inheritance Definition: Inheritance is transitive relation, allow classes to be defined in terms of other classes A derived class extends its base class It can add new members but cannot remove derived ones Declaring new members with the same name or signature hides the inherited ones A class can declare virtual methods and properties Derived classes can override the implementation of these members
- 14. Abstract Class An abstract class is a class that is declared abstract —it may or may not include abstract methods. Abstract classes cannot be instantiated, but they can be subclassed. When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class.
- 15. Example: Class 1: Class 2:
- 16. Association Association establish relationship between two classes through their objects. The relationship can be one to one, One to many, many to one and many to many.
- 17. Example
- 18. Polymorphism “Poly”= Many, “Morphism”= forms Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object. .
- 19. Polymorphism Cont… Polymorphism ability to take more than one form (objects have more than one type) A class can be used through its parent interface A child class may override some of the behaviors of the parent class Polymorphism allows abstract operations to be defined and used Abstract operations are defined in the base class' interface and implemented in the child classes
- 20. Example
- 21. Interface An interface in java is a blueprint of a class. It has static constants and abstract methods only. The interface in java is a mechanism to achieve fully abstraction. There can be only abstract methods in the java interface not method body. It is used to achieve fully abstraction and multiple inheritance in Java. Java Interface also represents a relationship. It cannot be instantiated just like abstract class.
- 22. Use of Java interface It is used to achieve fully abstraction. By interface, we can support the functionality of multiple inheritance. It can be used to achieve loose coupling.
- 23. Example
- 24. Exception Handling The exception handling in java is one of the powerful mechanism to handle the runtime errors so that normal flow of the application can be maintained. There are three types of Exception Handling I. Checked Exception II. Unchecked Exception III. Error
- 25. Exception Handling Cont…. 1) Checked Exception: The classes that extend Throwable class except RuntimeException and Error are known as checked exceptions e.g. IOException, SQLException etc. Checked exceptions are checked at compile-time. 2) Unchecked Exception: The classes that extend RuntimeException are known as unchecked exceptions e.g. ArithmeticException, NullPointerException, ArrayIndexOutOfBoundsException etc. Unchecked exceptions are not checked at compile-time rather they are checked at runtime. 3) Error: Error is irrecoverable e.g. OutOfMemoryError, VirtualMachineError, AssertionError etc.
- 26. Exception Handling Cont…. There are 5 keywords used in java exception handling. I. Try II. Catch III. Finally IV. Throw V. Throws
- 27. Example
- 28. Have a Good Day! For contact: facebook.com/pritom.chaki.77 [email protected]