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Object oriented fundamentals_in_java

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The document provides an introduction to object-oriented programming fundamentals in Java. It defines key concepts like object, class, abstraction, encapsulation, polymorphism, and inheritance. It explains that objects are instances of classes, and classes provide blueprints to generate objects. The document also gives examples of how objects are created from classes and their attributes and behaviors. It outlines characteristics of OOP like abstraction, encapsulation, and polymorphism. Finally, it mentions some common OOP design principles.

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Object-Oriented Programming Fundamentals in Java by George Wang
Objectives Definition of Object Oriented, Object, Class and relationship between Object and Class General structure of a Class How Objects are created and used Characteristics of Object Oriented Programming
What is Object-Oriented Programming? "Object oriented" means that we organize software as a collection of discrete objects that have both data and structure Example: to go From point A to point B Non OO: Drive(200 miles) (just do it) OO: myCar =new HondaAccord(); myCar.drive(200miles)
What is Object-Oriented Programming - continued
Why Object-Oriented Programming? Software Development is inherently a complex process. from OO Analysis and Design by Grady Booch, 2nd Edition
What is Object? 1) Object: eveything in the world is an object - concrete or conceptual. It is an instance of a Class 2) Object Can be real-world objects: this desk, this ballpen,etc Can represent GUI (Graphical User Interface) components Can represent software entities (events, files, images, etc.) Can represent abstract concepts (for example, rules of a game, a particular type of dance, etc.) ---Ask students: can anyone give an example of some Objects???
What is Class? a factory or blueprint that define a similar type or group of objects example: HondaAccordCar, Boeing747Airplane
Relation between Object and Class Object Class has identity, a a blueprint or unique instance of factory that holds a Class or produce the objects dynamic, static structure generated in written by runtime programmers
a Class Example import java.awt.color; public class HondaAccord { private Color carColor; public HondaAccord(Color carColor){ this.carColor= carColor; } public void Drive(int miles){ ... } }
Usage example public class CarUsageExample{ public static void main(Strings args[]){ HondaAccord myBlueHonda= new HondaAccord(Color.blue); myBlueHonda.drive(200); //go 200 miles } }
Characteristics of OO Programming Abstraction: focus on the essential characteristics of an object that distinguish it from others, relative to the perspective of the viewer Encapsulation: detail or implementation hidden so that only interface exposed Polymorphism: same function name can have different behavior depending on its subtype (airplane.travel() vs car. travel()) Inheritance: is-a relationship
OO design principles SRP- single responsibility (high cohesion): a class should have one reason to change OCP-open-close: class should be open to extension, close to modification LSP- Liskov substitution: subtype is-a basetype, therefore can substitute for it. DIP - dependency inversion: code to (depend to) interface (high level modules should not depend on low level modules) ISP-interface segregation principle: when there is incohesion, separate them into different interfaces -from Agile Software Development by Robert Martin

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Object oriented fundamentals_in_java

  • 1. Object-Oriented Programming Fundamentals in Java by George Wang
  • 2. Objectives Definition of Object Oriented, Object, Class and relationship between Object and Class General structure of a Class How Objects are created and used Characteristics of Object Oriented Programming
  • 3. What is Object-Oriented Programming? "Object oriented" means that we organize software as a collection of discrete objects that have both data and structure Example: to go From point A to point B Non OO: Drive(200 miles) (just do it) OO: myCar =new HondaAccord(); myCar.drive(200miles)
  • 4. What is Object-Oriented Programming - continued
  • 5. Why Object-Oriented Programming? Software Development is inherently a complex process. from OO Analysis and Design by Grady Booch, 2nd Edition
  • 6. What is Object? 1) Object: eveything in the world is an object - concrete or conceptual. It is an instance of a Class 2) Object Can be real-world objects: this desk, this ballpen,etc Can represent GUI (Graphical User Interface) components Can represent software entities (events, files, images, etc.) Can represent abstract concepts (for example, rules of a game, a particular type of dance, etc.) ---Ask students: can anyone give an example of some Objects???
  • 7. What is Class? a factory or blueprint that define a similar type or group of objects example: HondaAccordCar, Boeing747Airplane
  • 8. Relation between Object and Class Object Class has identity, a a blueprint or unique instance of factory that holds a Class or produce the objects dynamic, static structure generated in written by runtime programmers
  • 9. a Class Example import java.awt.color; public class HondaAccord { private Color carColor; public HondaAccord(Color carColor){ this.carColor= carColor; } public void Drive(int miles){ ... } }
  • 10. Usage example public class CarUsageExample{ public static void main(Strings args[]){ HondaAccord myBlueHonda= new HondaAccord(Color.blue); myBlueHonda.drive(200); //go 200 miles } }
  • 11. Characteristics of OO Programming Abstraction: focus on the essential characteristics of an object that distinguish it from others, relative to the perspective of the viewer Encapsulation: detail or implementation hidden so that only interface exposed Polymorphism: same function name can have different behavior depending on its subtype (airplane.travel() vs car. travel()) Inheritance: is-a relationship
  • 12. OO design principles SRP- single responsibility (high cohesion): a class should have one reason to change OCP-open-close: class should be open to extension, close to modification LSP- Liskov substitution: subtype is-a basetype, therefore can substitute for it. DIP - dependency inversion: code to (depend to) interface (high level modules should not depend on low level modules) ISP-interface segregation principle: when there is incohesion, separate them into different interfaces -from Agile Software Development by Robert Martin