Object_Oriented_Programming_combined.ppt
- 1. Introduction to Object Oriented Programming Gayathri Namasivayam Introduction to OOP
- 2. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 3. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 4. Why use OOP? ●Object Oriented Programming (OOP) is one of the most widely used programming paradigm ●Why is it extensively used? ● Well suited for building trivial and complex applications ● Allows re-use of code thereby increasing productivity ● New features can be easily built into the existing code ● Reduced production cost and maintenance cost ●Common programming languages used for OOP include C++, Java, and C# Introduction to OOP
- 5. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 6. Building Blocks of OOP: Objects & Classes ●Object: models a ● Real world object (ex. computer, book, box) ● Concept (ex. meeting, interview) ● Process (ex. sorting a stack of papers or comparing two computers to measure their performance) ●Class: prototype or blueprint from which objects are created Introduction to OOP
- 7. Building Blocks of OOP: Objects & Classes ●Class has ● Set of attributes or properties that describes every object ● Set of behavior or actions that every object can perform ●Object has ● Set of data (value for each of its attribute) ● Set of actions that it can perform ● An identity ●Every object belongs to a class Introduction to OOP
- 8. Real World Example of Objects & Classes Object: FordCar1 Behavior Start, Accelerate, Reverse, Stop Attributes Color: Yellow Type: Coupe Model: Mustang Cylinder: 6 Attributes Color, Type, Model, Cylinder Behavior Start, Accelerate, Reverse, Stop Class: FordCar Behavior Start, Accelerate, Reverse, Stop Attributes Color: Orange Type: Coupe Model: Focus Cylinder: 4 Object: FordCar2 Introduction to OOP
- 9. Another Real World Example.. Attributes Name, Height, Age Behavior Speak, Listen, Eat, Run, Walk Class: Person Object: Person1 Attributes Name: Ann Height: 5’ 4” Age: 21 Behavior Speak, Listen, Eat, Run, Walk Attributes Name: Adam Height: 5’ 9” Age: 24 Behavior Speak, Listen, Eat, Run, Walk Object: Person2 Introduction to OOP
- 10. Class ●A class is a set of variables (to represent its attributes) and functions (to describe its behavior) that act on its variables Introduction to OOP
- 11. Class ShippingBox int shipping_cost() { return cost_per_pound*weight; } sender_name : string receiver_name : string cost_per_pound : int weight : int shipping_cost() : int Introduction to OOP
- 12. Object ●Object is an instance of a class that holds data (values) in its variables. Data can be accessed by its functions Introduction to OOP
- 13. Objects of ShippingBox class sender_name = Jim receiver_name = John cost_per_pound = 5 weight = 10 shipping_cost() Object BoxB Object BoxA sender_name = Julie receiver_name = Jill cost_per_pound = 2 weight = 5 shipping_cost() Class ShippingBox Introduction to OOP
- 14. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 15. What is OOP? ●Paradigm for problem solving by interaction among objects ●It follows a natural way of solving problems ● Ex. Ann wants to start her car (1) Ann walks to her car (2) Ann sends a message to the car to start by turning on the ignition (3)The car starts Introduction to OOP
- 16. Problem Solving in OOP Problem: Ann wants to start her car Name = Ann Age = 21 Speak() Run() Walk() Object Ann Color = Yellow Type = Coupe Model = Mustang Cylinder = 6 Start() Accelerate() Stop() Object Ann’s car Introduction to OOP
- 17. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 18. Abstraction ●Extracting essential properties and behavior of an entity ●Class represents such an abstraction and is commonly referred to as an abstract data type Ex. In an application that computes the shipping cost of a box, we extract its properties: cost_per_pound, weight and its behavior: shipping_cost() Introduction to OOP
- 19. Abstraction sender_name : string receiver_name : string cost_per_pound : int weight : int shipping_cost() : int Class Shipping Box Attributes Sender’s name, Receiver’s name, Cost of shipping per pound, Weight Behavior Calculate shipping cost Abstraction Introduction to OOP
- 20. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 21. Encapsulation sender_name receiver_name cost_per_pound weight shipping_cost() ●Mechanism by which we combine data and the functions that manipulate the data into one unit ●Objects & Classes enforce encapsulation Introduction to OOP
- 22. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism ●Advantages vs Disadvantages ●Conclusion Introduction to OOP
- 23. Inheritance ●Create new classes (derived classes) from existing classes (base classes) ●The derived class inherits the variables and functions of the base class and adds additional ones! ●Provides the ability to re-use existing code Introduction to OOP
- 24. Inheritance Example BankAccount CheckingAccount SavingsAccount customer_name : string account_type : string balance : int insufficient_funds_fee : int deposit() : int withdrawal() : int process_deposit() : int customer_name : string account_type : string balance : int deposit() : int withdrawal() : int customer_name : string account_type : string balance : int interest_rate : int deposit() : int withdrawal() : int calculate_interest() : int Introduction to OOP
- 25. Inheritance Example interest_rate : int calculate_interest() : int insufficient_funds_fee : int process_deposit() : int CheckingAccount SavingsAccount customer_name : string account_type : string balance : int deposit() : int withdrawal() : int BankAccount Introduction to OOP
- 26. Topics ●Why use OOP? ●Building blocks of OOP ● Classes ● Objects ●What is OOP? ●OOP concepts ● Abstraction ● Encapsulation ● Inheritance ● Polymorphism* ●Advantages vs Disadvantages ●Conclusion (* To be covered in the next class) Introduction to OOP
- 27. Disadvantages of OOP ●Initial extra effort needed in accurately modeling the classes and sub-classes for a problem ●Suited for modeling certain real world problems as opposed to some others Introduction to OOP
- 28. Conclusion ●Classes & Objects ●Concepts in OOP ● Abstraction ● Encapsulation ● Inheritance ●Advantages & Disadvantages ●Next class ● Be prepared for an in-class activity (based on topics covered today)! ● Polymorphism in OOP! Introduction to OOP
- 29. Thank you! Introduction to OOP