Inheritance and Polymorphism
|
|
- Piers Fitzgerald
- 5 years ago
- Views:
Transcription
1 Object Oriented Programming Designed and Presented by Dr. Ayman Elshenawy Elsefy Dept. of Systems & Computer Eng.. Al-Azhar University Website: eaymanelshenawy.wordpress.com eaymanelshenawy@azhar.edu.eg eaymanelshenawy@yahoo.com eaymanelshenawy@gmail.com Lecture 4 Inheritance and Polymorphism 1
2 Objectives IN THIS Lecture, YOU WILL: Learn about inheritance Learn about subclasses and superclasses Explore how to override the methods of a superclass Examine how constructors of superclasses and subclasses work Learn about polymorphism Examine abstract classes Become familiar with interfaces Learn about composition 4 Encapsulation: OOP you can combine data and operations on that data in a single unit Operations can (directly) access the data, but the internal state of an object cannot be manipulated directly. 5 2
3 Inheritance You can create new classes from an existing classes. subclass (Circle) can extend base class (Shape). subclass (Car) can extend base class (vehicle). The new created class is called a subclass /derived class; The original class is called super or base class Reuse the code and save the programmer time. Inheritance ( is-a relationship) Composition (aggregation) ( has-a relationship) Many common features Best class design to avoid redundancy? 6 Inheritance The inheritance hierarchy describes a relationship between entities. A poodle is a dog, which is a mammal, which is an animal. A poodle has the same properties as a dog and can do anything a dog can do PartTimeEmployee (pay rate, and number of hours worked) is a person (first name, and last name) Able to extend the definition of the class Person by adding additional members (data and/or methods). 7 3
4 public class Person { private String firstname; //store the first name private String lastname; //store the last name //Default constructor; //Initialize firstname and lastname to empty string. public Person() { firstname = ""; lastname = ""; } //Set firstname and lastname public Person(String first, String last){ setname(first, last); } //Method to output the first name and last name public String tostring(){ return (firstname + " " + lastname); } //Method to set firstname and lastname public void setname(string first, String last) { firstname = first; lastname = last; } //Method to return the firstname public String getfirstname() { return firstname; } Inheritance } //Method to return the lastname public String getlastname(){ return lastname; } 8 Inheritance Shape is the superclass. The classes Circle and Rectangle are derived classes from Shape, and the class Square is derived class from Rectangle. Every Circle and every Rectangle is a Shape. Every Square is a Rectangle. 9 4
5 Super class and sub class rules 1. The private members of the superclass are private to the superclass; hence, the members of the subclass(es) cannot access them directly. 2. The subclass can directly access the public members of the superclass. 3. The subclass can include additional data and/or method members. 4. The subclass can override (redefine) the public methods of the superclass. The same method, number, and types of may be exist in the sub-class. Only affect objects of the subclass, not to the objects of the superclass. 5. All data members/methods of the superclass are also data members of the subclass (unless overridden). 10 single inheritance and multiple inheritance Single inheritance: the subclass is derived from a single superclass; Multiple inheritance, the subclass is derived from more than one superclass. Java supports only single inheritance; that is, in Java a class can extend the definition of only one class. 11 5
6 single inheritance and multiple inheritance Single inheritance: the subclass is derived from a single superclass; Multiple inheritance, the subclass is derived from more than one superclass. Java supports only single inheritance; that is, in Java a class can extend the definition of only one class. 12 Overriding A class SubClass is derived from a class SuperClass. The SubClass data and methods are the SuperClass data and methods + its own data and methods. Overriding : adding a method with the same signature as given by the superclass. To override a public method of the superclass in the subclass, the corresponding method in the subclass must have the same name, type, and parameter list. Overloading: If the corresponding method in the superclass and the subclass has the same name but different parameter lists, then this is method overloading in the subclass, which is also allowed. Whether you override or overload a method of the superclass in the subclass, you must know call to the superclass that has the same name as that used by a method of the subclass. 13 6
7 Rectangle Example UML class diagram of the class Rectangle. Rectangle Example 7
8 Class Box Example The class Box overrides the methods tostring and area, and overloads the method setdimension. Class Box Example 8
9 Keyword: super How to access superclass? keyword super refers to the superclass super can be used: To call a superclass constructor To call a superclass method To call an override method use Super.methodName(parms) To call non-override method Use the name of the method and parameters. 18 Keyword: super 19 9
10 Keyword: super 20 Are superclass s Constructors Inherited? No. They are not inherited. How to invoke superclass s constructors? Explicitly using the super keyword. Implicitly call the no-arg constructor if it exists. (Otherwise: compilation error) 21 10
11 Superclass s Constructor Is Always Invoked Subclass s constructor may invoke any of superclass s constructors. If none invoked explicitly, super() inserted at beginning. public A() { } is equivalent to public A() { super(); } public A(double d) { // some statements } is equivalent to public A(double d) { super(); // some statements } 22 Keyword: super (explicitly) specify a call to the default constructor of the class Rectangle, Use the reserved word super with no parameters, Call to the (default) constructor of the superclass must be the first statement. When this constructor of Box executes, it triggers the execution of the constructor with two parameters of type double of the class Rectangle
12 How Super class and sub-class works
13 26 CAUTION You must use the keyword super to call the superclass constructor. Syntax error: Invoking superclass s constructor by name in subclass. Call to a superclass constructor must appear first in constructor
14 public class Person { private String firstname; //store the first name private String lastname; //store the last name //Default constructor; //Initialize firstname and lastname to empty string. public Person() { firstname = ""; lastname = ""; } //Set firstname and lastname public Person(String first, String last){ setname(first, last); } //Method to output the first name and last name public String tostring(){ return (firstname + " " + lastname); } //Method to set firstname and lastname public void setname(string first, String last) { firstname = first; lastname = last; } //Method to return the firstname public String getfirstname() { return firstname; } Inheritance } //Method to return the lastname public String getlastname(){ return lastname; } 28 Inheritance 29 14
15 PartTimeEmployee Constructors
16 Protected Members of class if a member of a superclass needs to be accessed directly (only) by a subclass, that member is declared using the modifier protected
Object Oriented Programming. Java-Lecture 11 Polymorphism
Object Oriented Programming Java-Lecture 11 Polymorphism Abstract Classes and Methods There will be a situation where you want to develop a design of a class which is common to many classes. Abstract class
More informationLecture Contents CS313D: ADVANCED PROGRAMMING LANGUAGE. What is Inheritance?
CS313D: ADVANCED PROGRAMMING LANGUAGE Computer Science department Lecture 5: Inheritance & Polymorphism Lecture Contents 2 What is Inheritance? Super-class & sub class Protected members Creating subclasses
More informationCREATED BY: Muhammad Bilal Arslan Ahmad Shaad. JAVA Chapter No 5. Instructor: Muhammad Naveed
CREATED BY: Muhammad Bilal Arslan Ahmad Shaad JAVA Chapter No 5 Instructor: Muhammad Naveed Muhammad Bilal Arslan Ahmad Shaad Chapter No 5 Object Oriented Programming Q: Explain subclass and inheritance?
More informationCS-202 Introduction to Object Oriented Programming
CS-202 Introduction to Object Oriented Programming California State University, Los Angeles Computer Science Department Lecture III Inheritance and Polymorphism Introduction to Inheritance Introduction
More informationCS313D: ADVANCED PROGRAMMING LANGUAGE
CS313D: ADVANCED PROGRAMMING LANGUAGE Computer Science department Lecture 5: Inheritance & Polymorphism Lecture Contents 2 What is Inheritance? Super-class & sub class Protected members Creating subclasses
More informationInheritance. Inheritance Reserved word protected Reserved word super Overriding methods Class Hierarchies Reading for this lecture: L&L
Inheritance Inheritance Reserved word protected Reserved word super Overriding methods Class Hierarchies Reading for this lecture: L&L 9.1 9.4 1 Inheritance Inheritance allows a software developer to derive
More informationBBM 102 Introduction to Programming II Spring Inheritance
BBM 102 Introduction to Programming II Spring 2018 Inheritance 1 Today Inheritance Notion of subclasses and superclasses protected members UML Class Diagrams for inheritance 2 Inheritance A form of software
More informationAssoc. Prof. Marenglen Biba. (C) 2010 Pearson Education, Inc. All rights reserved.
Assoc. Prof. Marenglen Biba (C) 2010 Pearson Education, Inc. All Inheritance A form of software reuse in which a new class is created by absorbing an existing class s members and enriching them with
More informationINHERITANCE & POLYMORPHISM. INTRODUCTION IB DP Computer science Standard Level ICS3U. INTRODUCTION IB DP Computer science Standard Level ICS3U
C A N A D I A N I N T E R N A T I O N A L S C H O O L O F H O N G K O N G INHERITANCE & POLYMORPHISM P2 LESSON 12 P2 LESSON 12.1 INTRODUCTION inheritance: OOP allows a programmer to define new classes
More informationProgramming II (CS300)
1 Programming II (CS300) Chapter 05: Inheritance and Interfaces MOUNA KACEM mouna@cs.wisc.edu Fall 2018 Inheritance and Interfaces 2 Introduction Inheritance and Class Hierarchy Polymorphism Abstract Classes
More informationInheritance -- Introduction
Inheritance -- Introduction Another fundamental object-oriented technique is called inheritance, which, when used correctly, supports reuse and enhances software designs Chapter 8 focuses on: the concept
More informationCS313D: ADVANCED PROGRAMMING LANGUAGE
CS313D: ADVANCED PROGRAMMING LANGUAGE Computer Science department Lecture 4(b): Inheritance & Polymorphism Lecture Contents What is Inheritance? Super-class & sub class The object class Using extends keyword
More informationJava Object Oriented Design. CSC207 Fall 2014
Java Object Oriented Design CSC207 Fall 2014 Design Problem Design an application where the user can draw different shapes Lines Circles Rectangles Just high level design, don t write any detailed code
More informationPROGRAMMING LANGUAGE 2
31/10/2013 Ebtsam Abd elhakam 1 PROGRAMMING LANGUAGE 2 Java lecture (7) Inheritance 31/10/2013 Ebtsam Abd elhakam 2 Inheritance Inheritance is one of the cornerstones of object-oriented programming. It
More informationOVERRIDING. 7/11/2015 Budditha Hettige 82
OVERRIDING 7/11/2015 (budditha@yahoo.com) 82 What is Overriding Is a language feature Allows a subclass or child class to provide a specific implementation of a method that is already provided by one of
More informationLecture 18 CSE11 Fall 2013 Inheritance
Lecture 18 CSE11 Fall 2013 Inheritance What is Inheritance? Inheritance allows a software developer to derive a new class from an existing one write code once, use many times (code reuse) Specialization
More informationPolymorphism and Inheritance
Walter Savitch Frank M. Carrano Polymorphism and Inheritance Chapter 8 Objectives Describe polymorphism and inheritance in general Define interfaces to specify methods Describe dynamic binding Define and
More informationObject Oriented Features. Inheritance. Inheritance. CS257 Computer Science I Kevin Sahr, PhD. Lecture 10: Inheritance
CS257 Computer Science I Kevin Sahr, PhD Lecture 10: Inheritance 1 Object Oriented Features For a programming language to be called object oriented it should support the following features: 1. objects:
More informationCS1150 Principles of Computer Science Objects and Classes
CS1150 Principles of Computer Science Objects and Classes Yanyan Zhuang Department of Computer Science http://www.cs.uccs.edu/~yzhuang CS1150 UC. Colorado Springs Object-Oriented Thinking Chapters 1-8
More information8. Polymorphism and Inheritance
8. Polymorphism and Inheritance Harald Gall, Prof. Dr. Institut für Informatik Universität Zürich http://seal.ifi.uzh.ch/info1 Objectives Describe polymorphism and inheritance in general Define interfaces
More informationInheritance. Transitivity
Inheritance Classes can be organized in a hierarchical structure based on the concept of inheritance Inheritance The property that instances of a sub-class can access both data and behavior associated
More informationChapter 5 Object-Oriented Programming
Chapter 5 Object-Oriented Programming Develop code that implements tight encapsulation, loose coupling, and high cohesion Develop code that demonstrates the use of polymorphism Develop code that declares
More informationObject Oriented Programming is a programming method that combines: Advantage of Object Oriented Programming
Overview of OOP Object Oriented Programming is a programming method that combines: a) Data b) Instructions for processing that data into a self-sufficient object that can be used within a program or in
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Inheritance Introduction Generalization/specialization Version of January 20, 2014 Abstract
More informationInheritance, Polymorphism, and Interfaces
Inheritance, Polymorphism, and Interfaces Chapter 8 Inheritance Basics (ch.8 idea) Inheritance allows programmer to define a general superclass with certain properties (methods, fields/member variables)
More informationChapter 10 Classes Continued. Fundamentals of Java
Chapter 10 Classes Continued Objectives Know when it is appropriate to include class (static) variables and methods in a class. Understand the role of Java interfaces in a software system and define an
More information24. Inheritance. Java. Fall 2009 Instructor: Dr. Masoud Yaghini
24. Inheritance Java Fall 2009 Instructor: Dr. Masoud Yaghini Outline Superclasses and Subclasses Using the super Keyword Overriding Methods The Object Class References Superclasses and Subclasses Inheritance
More informationPractice for Chapter 11
Practice for Chapter 11 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Object-oriented programming allows you to derive new classes from existing
More informationInheritance. Finally, the final keyword. A widely example using inheritance. OOP: Inheritance 1
Inheritance Reuse of code Extension and intension Class specialization and class extension Inheritance The protected keyword revisited Inheritance and methods Method redefinition The composite design pattern
More informationGraphical Interface and Application (I3305) Semester: 1 Academic Year: 2017/2018 Dr Antoun Yaacoub
Lebanese University Faculty of Science Computer Science BS Degree Graphical Interface and Application (I3305) Semester: 1 Academic Year: 2017/2018 Dr Antoun Yaacoub 2 Crash Course in JAVA Classes A Java
More information22. Inheritance. Java. Summer 2008 Instructor: Dr. Masoud Yaghini
22. Inheritance Java Summer 2008 Instructor: Dr. Masoud Yaghini Outline Superclasses and Subclasses Using the super Keyword Overriding Methods The Object Class References Inheritance Object-oriented programming
More informationFull file at Chapter 2 - Inheritance and Exception Handling
Chapter 2 - Inheritance and Exception Handling TRUE/FALSE 1. The superclass inherits all its properties from the subclass. ANS: F PTS: 1 REF: 76 2. Private members of a superclass can be accessed by a
More informationCS111: PROGRAMMING LANGUAGE II
1 CS111: PROGRAMMING LANGUAGE II Computer Science Department Lecture 8(b): Abstract classes & Polymorphism Lecture Contents 2 Abstract base classes Concrete classes Polymorphic processing Dr. Amal Khalifa,
More informationCOMP 110/L Lecture 19. Kyle Dewey
COMP 110/L Lecture 19 Kyle Dewey Outline Inheritance extends super Method overriding Automatically-generated constructors Inheritance Recap -We talked about object-oriented programming being about objects
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Inheritance Introduction Generalization/specialization Version of January 21, 2013 Abstract
More informationProgramming II (CS300)
1 Programming II (CS300) Chapter 05: Inheritance and Interfaces MOUNA KACEM mouna@cs.wisc.edu Spring 2018 Inheritance and Interfaces 2 Introduction Inheritance and Class Hierarchy Polymorphism Abstract
More informationInheritance and Interfaces
Inheritance and Interfaces Object Orientated Programming in Java Benjamin Kenwright Outline Review What is Inheritance? Why we need Inheritance? Syntax, Formatting,.. What is an Interface? Today s Practical
More informationProgramming in C# Inheritance and Polymorphism
Programming in C# Inheritance and Polymorphism C# Classes Classes are used to accomplish: Modularity: Scope for global (static) methods Blueprints for generating objects or instances: Per instance data
More informationHAS-A Relationship. Association is a relationship where all objects have their own lifecycle and there is no owner.
HAS-A Relationship Association is a relationship where all objects have their own lifecycle and there is no owner. For example, teacher student Aggregation is a specialized form of association where all
More informationClass Hierarchy and Interfaces. David Greenstein Monta Vista High School
Class Hierarchy and Interfaces David Greenstein Monta Vista High School Inheritance Inheritance represents the IS-A relationship between objects. an object of a subclass IS-A(n) object of the superclass
More informationCLASSES AND OBJECTS IN JAVA
Lesson 8 CLASSES AND OBJECTS IN JAVA (1) Which of the following defines attributes and methods? (a) Class (b) Object (c) Function (d) Variable (2) Which of the following keyword is used to declare Class
More informationInheritance and Interfaces
Inheritance and Interfaces what is inheritance? examples & Java API examples inheriting a method overriding a method polymorphism Object tostring interfaces Ex: sorting and Comparable interface Inheritance
More informationIST311. Advanced Issues in OOP: Inheritance and Polymorphism
IST311 Advanced Issues in OOP: Inheritance and Polymorphism IST311/602 Cleveland State University Prof. Victor Matos Adapted from: Introduction to Java Programming: Comprehensive Version, Eighth Edition
More informationChapter 11 Inheritance and Polymorphism. Motivations. Suppose you will define classes to model circles,
Chapter 11 Inheritance and Polymorphism 1 Motivations Suppose you will define classes to model circles, rectangles, and triangles. These classes have many common features. What is the best way to design
More informationCS111: PROGRAMMING LANGUAGE II
1 CS111: PROGRAMMING LANGUAGE II Computer Science Department Lecture 4(b): Subclasses and Superclasses OOP OOP - Inheritance Inheritance represents the is a relationship between data types (e.g. student/person)
More informationJava Class Design. Eugeny Berkunsky, Computer Science dept., National University of Shipbuilding
Java Class Design Eugeny Berkunsky, Computer Science dept., National University of Shipbuilding eugeny.berkunsky@gmail.com http://www.berkut.mk.ua Objectives Implement encapsulation Implement inheritance
More informationMaking New instances of Classes
Making New instances of Classes NOTE: revised from previous version of Lecture04 New Operator Classes are user defined datatypes in OOP languages How do we make instances of these new datatypes? Using
More informationAbstract Classes. Abstract Classes a and Interfaces. Class Shape Hierarchy. Problem AND Requirements. Abstract Classes.
a and Interfaces Class Shape Hierarchy Consider the following class hierarchy Shape Circle Square Problem AND Requirements Suppose that in order to exploit polymorphism, we specify that 2-D objects must
More informationInf1-OP. Classes with Stuff in Common. Inheritance. Volker Seeker, adapting earlier version by Perdita Stevens and Ewan Klein.
Inf1-OP Inheritance UML Class Diagrams UML: language for specifying and visualizing OOP software systems UML class diagram: specifies class name, instance variables, methods,... Volker Seeker, adapting
More informationIntroduction to OOP with Java. Instructor: AbuKhleif, Mohammad Noor Sep 2017
Introduction to OOP with Java Instructor: AbuKhleif, Mohammad Noor Sep 2017 Lecture 11: Inheritance and Polymorphism Part 1 Instructor: AbuKhleif, Mohammad Noor Sep 2017 Instructor AbuKhleif, Mohammad
More informationInheritance. Unit 8. Summary. 8.1 Inheritance. 8.2 Inheritance: example. Inheritance Overriding of methods and polymorphism The class Object
Unit 8 Inheritance Summary Inheritance Overriding of methods and polymorphism The class Object 8.1 Inheritance Inheritance in object-oriented languages consists in the possibility of defining a class that
More informationWhat is Inheritance?
Inheritance 1 Agenda What is and Why Inheritance? How to derive a sub-class? Object class Constructor calling chain super keyword Overriding methods (most important) Hiding methods Hiding fields Type casting
More informationChapter 14 Abstract Classes and Interfaces
Chapter 14 Abstract Classes and Interfaces 1 What is abstract class? Abstract class is just like other class, but it marks with abstract keyword. In abstract class, methods that we want to be overridden
More informationECE 122. Engineering Problem Solving with Java
ECE 122 Engineering Problem Solving with Java Lecture 17 Inheritance Overview Problem: Can we create bigger classes from smaller ones without having to repeat information? Subclasses: a class inherits
More informationClasses and Inheritance Extending Classes, Chapter 5.2
Classes and Inheritance Extending Classes, Chapter 5.2 Dr. Yvon Feaster Inheritance Inheritance defines a relationship among classes. Key words often associated with inheritance are extend and implements.
More informationInf1-OP. Inheritance. Volker Seeker, adapting earlier version by Perdita Stevens and Ewan Klein. March 12, School of Informatics
Inf1-OP Inheritance Volker Seeker, adapting earlier version by Perdita Stevens and Ewan Klein School of Informatics March 12, 2018 UML Class Diagrams UML: language for specifying and visualizing OOP software
More informationProgramming using C# LECTURE 07. Inheritance IS-A and HAS-A Relationships Overloading and Overriding Polymorphism
Programming using C# LECTURE 07 Inheritance IS-A and HAS-A Relationships Overloading and Overriding Polymorphism What is Inheritance? A relationship between a more general class, called the base class
More informationCS111: PROGRAMMING LANGUAGE II. Lecture 1: Introduction to classes
CS111: PROGRAMMING LANGUAGE II Lecture 1: Introduction to classes Lecture Contents 2 What is a class? Encapsulation Class basics: Data Methods Objects Defining and using a class In Java 3 Java is an object-oriented
More informationRelationships Between Real Things CSE 143. Common Relationship Patterns. Employee. Supervisor
CSE 143 Object & Class Relationships Inheritance Reading: Ch. 9, 14 Relationships Between Real Things Man walks dog Dog strains at leash Dog wears collar Man wears hat Girl feeds dog Girl watches dog Dog
More informationInheritance (continued) Inheritance
Objectives Chapter 11 Inheritance and Polymorphism Learn about inheritance Learn about subclasses and superclasses Explore how to override the methods of a superclass Examine how constructors of superclasses
More informationHAS-A Relationship. If A uses B, then it is an aggregation, stating that B exists independently from A.
HAS-A Relationship Association is a weak relationship where all objects have their own lifetime and there is no ownership. For example, teacher student; doctor patient. If A uses B, then it is an aggregation,
More informationInheritance and Polymorphism
Inheritance and Polymorphism Dr. M. G. Abbas Malik Assistant Professor Faculty of Computing and IT (North Jeddah Branch) King Abdulaziz University, Jeddah, KSA mgmalik@kau.edu.sa www.sanlp.org/malik/cpit305/ap.html
More informationObject Oriented Programming in Java. Jaanus Pöial, PhD Tallinn, Estonia
Object Oriented Programming in Java Jaanus Pöial, PhD Tallinn, Estonia Motivation for Object Oriented Programming Decrease complexity (use layers of abstraction, interfaces, modularity,...) Reuse existing
More informationInheritance. OOP: Inheritance 1
Inheritance Reuse Extension and intension Class specialization and class extension Inheritance The protected keyword revisited Inheritance and methods Method redefinition An widely used inheritance example
More informationInheritance and Encapsulation. Amit Gupta
Inheritance and Encapsulation Amit Gupta Project 1 How did it go? What did you like about it? What did you not like? What can we do to help? Suggestions Ask questions if you don t understand a concept
More informationRelationships Between Real Things. CSE 143 Java. Common Relationship Patterns. Composition: "has a" CSE143 Sp Student.
CSE 143 Java Object & Class Relationships Inheritance Reading: Ch. 9, 14 Relationships Between Real Things Man walks dog Dog strains at leash Dog wears collar Man wears hat Girl feeds dog Girl watches
More informationRelationships Between Real Things CSC 143. Common Relationship Patterns. Composition: "has a" CSC Employee. Supervisor
CSC 143 Object & Class Relationships Inheritance Reading: Ch. 10, 11 Relationships Between Real Things Man walks dog Dog strains at leash Dog wears collar Man wears hat Girl feeds dog Girl watches dog
More informationCMSC 132: Object-Oriented Programming II
CMSC 132: Object-Oriented Programming II Java Support for OOP Department of Computer Science University of Maryland, College Park Object Oriented Programming (OOP) OO Principles Abstraction Encapsulation
More informationArgument Passing All primitive data types (int etc.) are passed by value and all reference types (arrays, strings, objects) are used through refs.
Local Variable Initialization Unlike instance vars, local vars must be initialized before they can be used. Eg. void mymethod() { int foo = 42; int bar; bar = bar + 1; //compile error bar = 99; bar = bar
More informationEncapsulation. Inf1-OOP. Getters and Setters. Encapsulation Again. Inheritance Encapsulation and Inheritance. The Object Superclass
Encapsulation Again Inheritance Encapsulation and Inheritance Inf1-OOP Inheritance and Interfaces Perdita Stevens, adapting earlier version by Ewan Klein School of Informatics March 9, 2015 The Object
More informationInstance Members and Static Members
Instance Members and Static Members You may notice that all the members are declared w/o static. These members belong to some specific object. They are called instance members. This implies that these
More informationInf1-OOP. Inheritance and Interfaces. Ewan Klein, Perdita Stevens. January 12, School of Informatics
Inf1-OOP Inheritance and Interfaces Ewan Klein, Perdita Stevens School of Informatics January 12, 2013 Encapsulation Again Inheritance Encapsulation and Inheritance The Object Superclass Flat vs. Nested
More informationCS5000: Foundations of Programming. Mingon Kang, PhD Computer Science, Kennesaw State University
CS5000: Foundations of Programming Mingon Kang, PhD Computer Science, Kennesaw State University Inheritance Three main programming mechanisms that constitute object-oriented programming (OOP) Encapsulation
More informationDay 4. COMP1006/1406 Summer M. Jason Hinek Carleton University
Day 4 COMP1006/1406 Summer 2016 M. Jason Hinek Carleton University today s agenda assignments questions about assignment 2 a quick look back constructors signatures and overloading encapsulation / information
More informationM301: Software Systems & their Development. Unit 4: Inheritance, Composition and Polymorphism
Block 1: Introduction to Java Unit 4: Inheritance, Composition and Polymorphism Aims of the unit: Study and use the Java mechanisms that support reuse, in particular, inheritance and composition; Analyze
More informationComputer Programming Inheritance 10 th Lecture
Computer Programming Inheritance 10 th Lecture 엄현상 (Eom, Hyeonsang) School of Computer Science and Engineering Seoul National University Copyrights 2015 Eom, Hyeonsang All Rights Reserved 순서 Inheritance
More informationCS111: PROGRAMMING LANGUAGE II
1 CS111: PROGRAMMING LANGUAGE II Computer Science Department Lecture 8(a): Abstract Classes Lecture Contents 2 Abstract base classes Concrete classes Dr. Amal Khalifa, 2014 Abstract Classes and Methods
More informationMore About Objects. Zheng-Liang Lu Java Programming 255 / 282
More About Objects Inheritance: passing down states and behaviors from the parents to their children. Interfaces: requiring objects for the demanding methods which are exposed to the outside world. Polymorphism
More informationInheritance and object compatibility
Inheritance and object compatibility Object type compatibility An instance of a subclass can be used instead of an instance of the superclass, but not the other way around Examples: reference/pointer can
More informationLecture 7: Classes and Objects CS2301
Lecture 7: Classes and Objects NADA ALZAHRANI CS2301 1 What is OOP? Object-oriented programming (OOP) involves programming using objects. An object represents an entity in the real world that can be distinctly
More informationCISC 3115 TY3. C09a: Inheritance. Hui Chen Department of Computer & Information Science CUNY Brooklyn College. 9/20/2018 CUNY Brooklyn College
CISC 3115 TY3 C09a: Inheritance Hui Chen Department of Computer & Information Science CUNY Brooklyn College 9/20/2018 CUNY Brooklyn College 1 Outline Inheritance Superclass/supertype, subclass/subtype
More informationCMSC 132: Object-Oriented Programming II
CMSC 132: Object-Oriented Programming II Java Support for OOP Department of Computer Science University of Maryland, College Park Object Oriented Programming (OOP) OO Principles Abstraction Encapsulation
More informationStarting Out with Java: From Control Structures Through Objects Sixth Edition
Starting Out with Java: From Control Structures Through Objects Sixth Edition Chapter 10 Inheritance Chapter Topics (1 of 2) 10.1 What Is Inheritance? 10.2 Calling the Superclass Constructor 10.3 Overriding
More informationInheritance Introduction. 9.1 Introduction 361
www.thestudycampus.com Inheritance 9.1 Introduction 9.2 Superclasses and Subclasses 9.3 protected Members 9.4 Relationship Between Superclasses and Subclasses 9.4.1 Creating and Using a CommissionEmployee
More informationCS111: PROGRAMMING LANGUAGE II
CS111: PROGRAMMING LANGUAGE II Computer Science Department Lecture 4&5: Inheritance Lecture Contents What is Inheritance? Super-class & sub class The object class Using extends keyword @override keyword
More informationInheritance. Lecture 11 COP 3252 Summer May 25, 2017
Inheritance Lecture 11 COP 3252 Summer 2017 May 25, 2017 Subclasses and Superclasses Inheritance is a technique that allows one class to be derived from another. A derived class inherits all of the data
More informationCreate a Java project named week9
Objectives of today s lab: Through this lab, students will explore a hierarchical model for object-oriented design and examine the capabilities of the Java language provides for inheritance and polymorphism.
More informationInheritance & Polymorphism
Inheritance & Polymorphism Procedural vs. object oriented Designing for Inheritance Test your Design Inheritance syntax **Practical ** Polymorphism Overloading methods Our First Example There will be shapes
More informationHAS-A Relationship. Association is a relationship where all objects have their own lifecycle and there is no owner.
HAS-A Relationship Association is a relationship where all objects have their own lifecycle and there is no owner. For example, teacher student Aggregation is a specialized form of association where all
More informationCOMP 110/L Lecture 20. Kyle Dewey
COMP 110/L Lecture 20 Kyle Dewey Outline super in methods abstract Classes and Methods Polymorphism super in Methods Recap You ve seen super in constructors... Recap You ve seen super in constructors...
More informationSubclass Gist Example: Chess Super Keyword Shadowing Overriding Why? L10 - Polymorphism and Abstract Classes The Four Principles of Object Oriented
Table of Contents L01 - Introduction L02 - Strings Some Examples Reserved Characters Operations Immutability Equality Wrappers and Primitives Boxing/Unboxing Boxing Unboxing Formatting L03 - Input and
More informationTopic 7: Inheritance. Reading: JBD Sections CMPS 12A Winter 2009 UCSC
Topic 7: Inheritance Reading: JBD Sections 7.1-7.6 1 A Quick Review of Objects and Classes! An object is an abstraction that models some thing or process! Examples of objects:! Students, Teachers, Classes,
More informationC++ Important Questions with Answers
1. Name the operators that cannot be overloaded. sizeof,.,.*,.->, ::,? 2. What is inheritance? Inheritance is property such that a parent (or super) class passes the characteristics of itself to children
More informationSoftware Paradigms (Lesson 3) Object-Oriented Paradigm (2)
Software Paradigms (Lesson 3) Object-Oriented Paradigm (2) Table of Contents 1 Reusing Classes... 2 1.1 Composition... 2 1.2 Inheritance... 4 1.2.1 Extending Classes... 5 1.2.2 Method Overriding... 7 1.2.3
More informationInheritance CSC9Y4. Inheritance
Inheritance CSC9Y4 1 Inheritance We start with a superclass from which a subclass can be derived. New attributes and methods can be defined in a subclass and existing methods re-defined. How do we know
More informationObject Oriented Programming: Based on slides from Skrien Chapter 2
Object Oriented Programming: A Review Based on slides from Skrien Chapter 2 Object-Oriented Programming (OOP) Solution expressed as a set of communicating objects An object encapsulates the behavior and
More informationObject Oriented Relationships
Lecture 3 Object Oriented Relationships Group home page: http://groups.yahoo.com/group/java CS244/ 2 Object Oriented Relationships Object oriented programs usually consisted of a number of classes Only
More informationChapter 7. Inheritance
Chapter 7 Inheritance Introduction to Inheritance Inheritance is one of the main techniques of objectoriented programming (OOP) Using this technique, a very general form of a class is first defined and
More informationObjective Questions. BCA Part III Paper XIX (Java Programming) page 1 of 5
Objective Questions BCA Part III page 1 of 5 1. Java is purely object oriented and provides - a. Abstraction, inheritance b. Encapsulation, polymorphism c. Abstraction, polymorphism d. All of the above
More informationConstructor. Liang, Introduction to Java Programming, Tenth Edition, (c) 2013 Pearson Education, Inc. All rights reserved.
Constructor Suppose you will define classes to model circles, rectangles, and triangles. These classes have many common features. What is the best way to design these classes so to avoid redundancy? The
More information