Some client code. output. subtype polymorphism As dynamic binding occurs the behavior (i.e., methods) follow the objects. Squarer
|
|
- Dale Carpenter
- 6 years ago
- Views:
Transcription
1 public class Base { protected int theint = 100; System.out.println( theint ); public class Doubler extends Base { System.out.println( theint*2 ); public class Tripler extends Base { System.out.println( theint*3 ); public class Squarer extends Tripler { System.out.println( theint*theint ); 2006 Pearson Addison-Wesley. All rights reserved Base thebase; thebase = new Base(); thebase = new Doubler(); thebase = new Tripler(); thebase = new Squarer(); thebase = new Base(); Some client code output Base subtype polymorphism As dynamic binding occurs the behavior (i.e., methods) follow the objects. Doubler Tripler Squarer 2006 Pearson Addison-Wesley. All rights reserved
2 Polymorphism comes from the words poly many morph to change A polymorphic variable can appear to change its type through dynamic binding. The compiler always understands a variable s type according to its declaration. The compiler permits some flexibility by way of type conformance. At run-time the behavior of a method call depends upon the type of the object and not the variable. thebase = new Squarer(); 2006 Pearson Addison-Wesley. All rights reserved Another Example of Polymorphism public class Sinker extends Component { public class SlugWithSink extends Sinker { setlocation( k, k ); public class BugWithSink extends Sinker { setsize( k, 10 ); public class RugWithSink extends Sinker { setlocation( 0, k ); Sinker sink; SlugWithSink slug; BugWithSink bug; RugWithSink rug; slug = new SlugWithSink(); rug = new RugWithSink(); bug = new BugWithSink(); sink = slug; sink.dothekitchensink(5); sink = bug; sink.dothekitchensink(10); sink = rug; sink.dothekitchensink(2); sink = slug; sink.dothekitchensink(3); What if Sinker does NOT include dothekitchensink()? 2006 Pearson Addison-Wesley. All rights reserved
3 Why is Polymorphism Useful? Polymorphism permits a superclass to capture commonality, leaving the specifics to subclasses. Suppose that JComponent included an area method, as shown. Then Rectangle could be written as and Oval could be written as public class JComponent { public double area() { return 0.0; public class Rectangle extends JComponent { public double area() { return getwidth() * getheight(); public class Oval extends JComponent { public double area() { return getwidth()/2. * getheight()/2. * Math.PI; now consider public double coveragecost( JComponent v, double costpersqunit) { return v.area() * costpersqunit; 2006 Pearson Addison-Wesley. All rights reserved Object Every class inherits from a class called Object. The println method is overloaded. One version of println is defined as follows. public void println( Object x ) { println( x.tostring() ); Object... «query» + boolean equals( Object ) + String tostring()... Oval could override tostring() in the following manner. public String tostring() { String result = "Oval object" + "\n"; result = result + " x: " + getx() +", y: "+gety(); result = result + " width: " + getwidth() +", height: "+getheight() + "\n"; if (getparent() == null) { result = result + " not added, \n"; else { result = result + " is added, \n"; result = result + " color: "+colorstring(getbackground()); return result; 2006 Pearson Addison-Wesley. All rights reserved
4 Equality There are two different kinds of equality for reference data. Identity equality means that two expressions have the same identity. (i.e., the two expressions represent the same object.) Content equality means that two expressions represent objects with the same value/content. The == symbol tests for identity equality, when applied to reference data. Example Oval ov1, ov2; ov1 = new Oval(0, 0, 100, 100); ov2 = new Oval(0, 0, 100, 100); if (ov1 == ov2) { System.out.println( identity equality ); else { System.out.println( not identity equality ); 2006 Pearson Addison-Wesley. All rights reserved Content Equality The equals method from Object provides a potential content equality check. Example public class MyOval extends Oval { public boolean equals(object z) { return (z instanceof Oval) && ((Oval)z).getX() == getx() && ((Oval)z).getY() == gety() && ((Oval)z).getWidth() == getwidth() && ((Oval)z).getHeight() == getheight() && ((Oval)z).getBackground() == getbackground() && ((Oval)z).getParent() == getparent(); 2006 Pearson Addison-Wesley. All rights reserved
5 Arrays are like Objects A whole (aggregate) array can be assigned to another array variable passed as a parameter private void colorallred( Rectangle[] rects ) { int ndx = 0; while ( ndx!= rects.length ) { rects[ndx].setbackground( Color.red ); ndx++; Rectangle[] somerects, otherrects; somerects = new Rectangle[3]; somerects[0] = new Rectangle(0,0,5,5); somerects[1] = new Rectangle(6,6,8,8); somerects[2] = new Rectangle(10,10,10,10); otherrects = somerects; colorallred( otherrects ); 2006 Pearson Addison-Wesley. All rights reserved Arrays are like Objects 2 Every array conforms to Object int[] myarray; myarray = (int[])makeanobject(); private Object makeanobject( ) { int[] daysinmonth = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ; processobject( daysinmonth ); return daysinmonth; private void processobject( Object stuff ) { 2006 Pearson Addison-Wesley. All rights reserved
6 Arrays are unlike Objects There is no way to override Object methods. tostring equals Inheritance of arrays is NOT permitted. public class myclass extends someclass[] 2006 Pearson Addison-Wesley. All rights reserved
Inheritance Systems. Merchandise. Television Camcorder Shirt Shoe Dress 9.1.1
Merchandise Inheritance Systems Electronics Clothing Television Camcorder Shirt Shoe Dress Digital Analog 9.1.1 Another AcademicDisciplines Hierarchy Mathematics Engineering Algebra Probability Geometry
More informationCS/120 Final Exam. Name
CS/120 Final Exam Name 16 pts 1. Trace the following segment of code and to the left of each System.out.println instruction show the precise output that results when this code segment executes. java.awt.container
More informationInheritance & Polymorphism Recap. Inheritance & Polymorphism 1
Inheritance & Polymorphism Recap Inheritance & Polymorphism 1 Introduction! Besides composition, another form of reuse is inheritance.! With inheritance, an object can inherit behavior from another object,
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 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 informationPlease show all of your work.
Please show all of your work. Name CS/120 Exam #2 Sample Exam 1. For each part below write the term, symbols, or phrase from class that best fits the description. (Each part is worth 2 points.) a) This
More informationChapter 10 Inheritance and Polymorphism. Dr. Hikmat Jaber
Chapter 10 Inheritance and Polymorphism Dr. Hikmat Jaber 1 Motivations Suppose you will define classes to model circles, rectangles, and triangles. These classes have many common features. What is the
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 informationPractice Midterm 1. Problem Points Score TOTAL 50
CS 120 Software Design I Spring 2019 Practice Midterm 1 University of Wisconsin - La Crosse February 25 NAME: Do not turn the page until instructed to do so. This booklet contains 10 pages including the
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Inheritance (part II) Polymorphism Version of January 21, 2013 Abstract These lecture notes
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 informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Inheritance (part II) Polymorphism Version of January 21, 2013 Abstract These lecture notes
More informationCOMP200 - Object Oriented Programming: Test One Duration - 60 minutes
COMP200 - Object Oriented Programming: Test One Duration - 60 minutes Study the following class and answer the questions that follow: package shapes3d; public class Circular3DShape { private double radius;
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 informationindex.pdf January 21,
index.pdf January 21, 2013 1 ITI 1121. Introduction to Computing II Circle Let s complete the implementation of the class Circle. Marcel Turcotte School of Electrical Engineering and Computer Science Version
More informationAbstract and final classes [Horstmann, pp ] An abstract class is kind of a cross between a class and an interface.
Abstract and final classes [Horstmann, pp. 490 491] An abstract class is kind of a cross between a class and an interface. In a class, all methods are defined. In an interface, methods are declared rather
More informationCS/ENGRD 2110 SPRING Lecture 2: Objects and classes in Java
1 CS/ENGRD 2110 SPRING 2014 Lecture 2: Objects and classes in Java http://courses.cs.cornell.edu/cs2110 Java OO (Object Orientation) 2 Python and Matlab have objects and classes. Strong-typing nature of
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 informationConstants are named in ALL_CAPS, using upper case letters and underscores in their names.
Naming conventions in Java The method signature Invoking methods All class names are capitalized Variable names and method names start with a lower case letter, but every word in the name after the first
More informationCOMP200 INHERITANCE. OOP using Java, from slides by Shayan Javed
1 1 COMP200 INHERITANCE OOP using Java, from slides by Shayan Javed 2 Inheritance Derive new classes (subclass) from existing ones (superclass). Only the Object class (java.lang) has no superclass Every
More informationCOMP 250. Lecture 32. polymorphism. Nov. 25, 2016
COMP 250 Lecture 32 polymorphism Nov. 25, 2016 1 Recall example from lecture 30 class String serialnumber Person owner void bark() {print woof } : my = new (); my.bark();?????? extends extends class void
More informationThe Liskov Substitution Principle
Agile Design Principles: The Liskov Substitution Principle Based on Chapter 10 of Robert C. Martin, Agile Software Development: Principles, Patterns, and Practices, Prentice Hall, 2003 and on Barbara Liskov
More informationLast class. -More on polymorphism -super -Introduction to interfaces
Last class -More on polymorphism -super -Introduction to interfaces Interfaces Sometimes in Java, we will have 2 classes that both share a similar structure, but neither of them is clearly the parent or
More informationAbstract Class. Lecture 21. Based on Slides of Dr. Norazah Yusof
Abstract Class Lecture 21 Based on Slides of Dr. Norazah Yusof 1 Abstract Class Abstract class is a class with one or more abstract methods. The abstract method Method signature without implementation
More informationCLASS DESIGN. Objectives MODULE 4
MODULE 4 CLASS DESIGN Objectives > After completing this lesson, you should be able to do the following: Use access levels: private, protected, default, and public. Override methods Overload constructors
More informationLecture Notes Chapter #9_b Inheritance & Polymorphism
Lecture Notes Chapter #9_b Inheritance & Polymorphism Inheritance results from deriving new classes from existing classes Root Class all java classes are derived from the java.lang.object class GeometricObject1
More informationCS Programming I: Inheritance
CS 200 - Programming I: Inheritance Marc Renault Department of Computer Sciences University of Wisconsin Madison Fall 2017 TopHat Sec 3 (PM) Join Code: 719946 TopHat Sec 4 (AM) Join Code: 891624 Inheritance
More informationMore about inheritance
Main concepts to be covered More about inheritance Exploring polymorphism method polymorphism static and dynamic type overriding dynamic method lookup protected access 4.1 The inheritance hierarchy Conflicting
More informationJFrame In Swing, a JFrame is similar to a window in your operating system
JFrame In Swing, a JFrame is similar to a window in your operating system All components will appear inside the JFrame window Buttons, text labels, text fields, etc. 5 JFrame Your GUI program must inherit
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Interface Abstract data types Version of January 26, 2013 Abstract These lecture notes are meant
More informationCSE 8B Programming Assignments Spring Programming: You will have 5 files all should be located in a dir. named PA3:
PROGRAMMING ASSIGNMENT 3: Read Savitch: Chapter 7 Programming: You will have 5 files all should be located in a dir. named PA3: ShapeP3.java PointP3.java CircleP3.java RectangleP3.java TriangleP3.java
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 informationInheritance. Inheritance
1 2 1 is a mechanism for enhancing existing classes. It allows to extend the description of an existing class by adding new attributes and new methods. For example: class ColoredRectangle extends Rectangle
More informationAdvanced Programming - JAVA Lecture 4 OOP Concepts in JAVA PART II
Advanced Programming - JAVA Lecture 4 OOP Concepts in JAVA PART II Mahmoud El-Gayyar elgayyar@ci.suez.edu.eg Ad hoc-polymorphism Outline Method overloading Sub-type Polymorphism Method overriding Dynamic
More informationCS/ENGRD 2110 FALL Lecture 2: Objects and classes in Java
1 CS/ENGRD 2110 FALL 2017 Lecture 2: Objects and classes in Java http://courses.cs.cornell.edu/cs2110 CMS VideoNote.com, PPT slides, DrJava 2 CMS. Visit course webpage, click Links, then CMS for 2110.
More informationObject Oriented Programming and Design in Java. Session 10 Instructor: Bert Huang
Object Oriented Programming and Design in Java Session 10 Instructor: Bert Huang Announcements Homework 2 due Mar. 3rd, 11 AM two days Midterm review Monday, Mar. 8th Midterm exam Wednesday, Mar. 10th
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 informationInheritance. CSE 142, Summer 2002 Computer Programming 1.
Inheritance CSE 142, Summer 2002 Computer Programming 1 http://www.cs.washington.edu/education/courses/142/02su/ 29-July-2002 cse142-14-inheritance 2002 University of Washington 1 Reading Readings and
More informationPowerPoint Slides. Object-Oriented Design Using JAVA. Chapter 2. by Dale Skrien
PowerPoint Slides Object-Oriented Design Using JAVA by Dale Skrien Chapter 2 Object-oriented Programming Divides the program into a set of communicating objects Encapsulates in an object all the behavior
More informationPractice Midterm 1 Answer Key
CS 120 Software Design I Fall 2018 Practice Midterm 1 Answer Key University of Wisconsin - La Crosse Due Date: October 5 NAME: Do not turn the page until instructed to do so. This booklet contains 10 pages
More informationMore Java Basics. class Vector { Object[] myarray;... //insert x in the array void insert(object x) {...} Then we can use Vector to hold any objects.
More Java Basics 1. INHERITANCE AND DYNAMIC TYPE-CASTING Java performs automatic type conversion from a sub-type to a super-type. That is, if a method requires a parameter of type A, we can call the method
More informationOutline. Inheritance. Abstract Classes Interfaces. Class Extension Overriding Methods Inheritance and Constructors Polymorphism.
Outline Inheritance Class Extension Overriding Methods Inheritance and Constructors Polymorphism Abstract Classes Interfaces 1 OOP Principles Encapsulation Methods and data are combined in classes Not
More informationName CS/120 Sample Exam #1 -- Riley. a) Every program has syntax, which refers to the form of the code, and, which refers to the meaning of the code.
Name CS/120 Sample Exam #1 -- Riley Please show all of your work. 1. For each part below write the term, symbols, or phrase from class that best fits the description. (Each part is worth 2 points.) a)
More informationAP Computer Science Chapter 10 Implementing and Using Classes Study Guide
AP Computer Science Chapter 10 Implementing and Using Classes Study Guide 1. A class that uses a given class X is called a client of X. 2. Private features of a class can be directly accessed only within
More informationIn this lab, you will be given the implementation of the classes GeometricObject, Circle, and Rectangle, as shown in the following UML class diagram.
Jordan University Faculty of Engineering and Technology Department of Computer Engineering Object-Oriented Problem Solving: CPE 342 Lab-8 Eng. Asma Abdel Karim In this lab, you will be given the implementation
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 informationReusing Classes. Hendrik Speleers
Hendrik Speleers Overview Composition Inheritance Polymorphism Method overloading vs. overriding Visibility of variables and methods Specification of a contract Abstract classes, interfaces Software development
More informationInheritance and Polymorphism. CSE 114, Computer Science 1 Stony Brook University
Inheritance and Polymorphism CSE 114, Computer Science 1 Stony Brook University http://www.cs.stonybrook.edu/~cse114 1 Motivation Model classes with similar properties and methods: Circles, rectangles
More informationCS/ENGRD 2110 SPRING Lecture 2: Objects and classes in Java
1 CS/ENGRD 2110 SPRING 2017 Lecture 2: Objects and classes in Java http://courses.cs.cornell.edu/cs2110 CMS VideoNote.com, PPT slides, DrJava, Book 2 CMS available. Visit course webpage, click Links, then
More informationProgramming 2. Inheritance & Polymorphism
Programming 2 Inheritance & Polymorphism Motivation Lame Shape Application public class LameShapeApplication { Rectangle[] therects=new Rectangle[100]; Circle[] thecircles=new Circle[100]; Triangle[] thetriangles=new
More informationProgramming Languages and Techniques (CIS120)
Programming Languages and Techniques (CIS120) Lecture 28 March 30, 2016 Collections and Equality Chapter 26 Announcements Dr. Steve Zdancewic is guest lecturing today He teaches CIS 120 in the Fall Midterm
More informationObject-Oriented Design Lecture 14 CSU 370 Fall 2007 (Pucella) Friday, Nov 2, 2007
Object-Oriented Design Lecture 14 CSU 370 Fall 2007 (Pucella) Friday, Nov 2, 2007 (These notes are very rough, and differ somewhat from what I presented in class; I am posting them here to supplemental
More informationChapter 6: Inheritance
Chapter 6: Inheritance EECS 1030 moodle.yorku.ca State of an object final int WIDTH = 3; final int HEIGTH = 4; final int WEIGHT = 80; GoldenRectangle rectangle = new GoldenRectangle(WIDTH, HEIGHT, WEIGHT);
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 informationCOMP 401 INHERITANCE: IS-A. Instructor: Prasun Dewan
COMP 401 INHERITANCE: IS-A Instructor: Prasun Dewan PREREQUISITE Interfaces Inheritance and Arrays 2 IS-A IS-A Relationship Human IS-A Mammal Salmon IS-A Fish ACartesianPoint IS-A Point T1 IS-A T2 if T1
More informationAdvanced Placement Computer Science. Inheritance and Polymorphism
Advanced Placement Computer Science Inheritance and Polymorphism What s past is prologue. Don t write it twice write it once and reuse it. Mike Scott The University of Texas at Austin Inheritance, Polymorphism,
More informationPolymorphism: Interfaces and Iteration. Fundamentals of Computer Science
Polymorphism: Interfaces and Iteration Fundamentals of Computer Science Outline A shape object hierarchy Classes that extend Versus classes that implements Java interfaces How Java handles multiple-inheritance
More informationObject 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 informationOverview. Lecture 7: Inheritance and GUIs. Inheritance. Example 9/30/2008
Overview Lecture 7: Inheritance and GUIs Written by: Daniel Dalevi Inheritance Subclasses and superclasses Java keywords Interfaces and inheritance The JComponent class Casting The cosmic superclass Object
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 informationCreating Java Programs with Greenfoot
Creating Java Programs with Greenfoot Defining Methods 1 Copyright 2012, Oracle and/or its affiliates. All rights Overview This lesson covers the following topics: Describe effective placement of methods
More informationCS 112 Programming 2. Lecture 06. Inheritance & Polymorphism (1) Chapter 11 Inheritance and Polymorphism
CS 112 Programming 2 Lecture 06 Inheritance & Polymorphism (1) Chapter 11 Inheritance and Polymorphism rights reserved. 2 Motivation Suppose you want to define classes to model circles, rectangles, and
More informationIslamic University of Gaza Faculty of Engineering Computer Engineering Department
Student Mark Islamic University of Gaza Faculty of Engineering Computer Engineering Department Question # 1 / 18 Question # / 1 Total ( 0 ) Student Information ID Name Answer keys Sector A B C D E A B
More informationCS 520 Theory and Practice of Software Engineering Fall 2018
Today CS 520 Theory and Practice of Software Engineering Fall 2018 Object Oriented (OO) Design Principles September 13, 2018 Code review and (re)design of an MVC application (and encapsulation) Polymorphism
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 informationThe class Object. Lecture CS1122 Summer 2008
The class Object http://www.javaworld.com/javaworld/jw-01-1999/jw-01-object.html Lecture 10 -- CS1122 Summer 2008 Review Object is at the top of every hierarchy. Every class in Java has an IS-A relationship
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 informationProgramming Languages and Techniques (CIS120)
Programming Languages and Techniques (CIS120) Lecture 36 April 23, 2014 Overriding and Equality HW 10 has a HARD deadline Announcements You must submit by midnight, April 30 th Demo your project to your
More informationFirst IS-A Relationship: Inheritance
First IS-A Relationship: Inheritance The relationships among Java classes form class hierarchy. We can define new classes by inheriting commonly used states and behaviors from predefined classes. A class
More informationCOS226 - Spring 2018 Class Meeting # 13 March 26, 2018 Inheritance & Polymorphism
COS226 - Spring 2018 Class Meeting # 13 March 26, 2018 Inheritance & Polymorphism Ibrahim Albluwi Composition A GuitarString has a RingBuffer. A MarkovModel has a Symbol Table. A Symbol Table has a Binary
More informationJava and OOP. Part 3 Extending classes. OOP in Java : W. Milner 2005 : Slide 1
Java and OOP Part 3 Extending classes OOP in Java : W. Milner 2005 : Slide 1 Inheritance Suppose we want a version of an existing class, which is slightly different from it. We want to avoid starting again
More informationCS/ENGRD 2110 SPRING Lecture 2: Objects and classes in Java
1 CS/ENGRD 2110 SPRING 2018 Lecture 2: Objects and classes in Java http://courses.cs.cornell.edu/cs2110 Homework HW1 2 The answers you handed in at the end of lecture 1 showed mass confusion! Perhaps 80%
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 informationCMSC131. Inheritance. Object. When we talked about Object, I mentioned that all Java classes are "built" on top of that.
CMSC131 Inheritance Object When we talked about Object, I mentioned that all Java classes are "built" on top of that. This came up when talking about the Java standard equals operator: boolean equals(object
More informationOBJECT ORİENTATİON ENCAPSULATİON
OBJECT ORİENTATİON Software development can be seen as a modeling activity. The first step in the software development is the modeling of the problem we are trying to solve and building the conceptual
More informationCS 251 Intermediate Programming Inheritance
CS 251 Intermediate Programming Inheritance Brooke Chenoweth University of New Mexico Spring 2018 Inheritance We don t inherit the earth from our parents, We only borrow it from our children. What is inheritance?
More informationClass, Variable, Constructor, Object, Method Questions
Class, Variable, Constructor, Object, Method Questions http://www.wideskills.com/java-interview-questions/java-classes-andobjects-interview-questions https://www.careerride.com/java-objects-classes-methods.aspx
More informationLecture 36: Cloning. Last time: Today: 1. Object 2. Polymorphism and abstract methods 3. Upcasting / downcasting
Lecture 36: Cloning Last time: 1. Object 2. Polymorphism and abstract methods 3. Upcasting / downcasting Today: 1. Project #7 assigned 2. equals reconsidered 3. Copying and cloning 4. Composition 11/27/2006
More informationChapter 11 Inheritance and Polymorphism
Chapter 11 Inheritance and Polymorphism 1 Motivations OOP is built on three principles: Encapsulation (classes/objects, discussed in chapters 9 and 10), Inheritance, and Polymorphism. Inheritance: Suppose
More informationCH. 2 OBJECT-ORIENTED PROGRAMMING
CH. 2 OBJECT-ORIENTED PROGRAMMING ACKNOWLEDGEMENT: THESE SLIDES ARE ADAPTED FROM SLIDES PROVIDED WITH DATA STRUCTURES AND ALGORITHMS IN JAVA, GOODRICH, TAMASSIA AND GOLDWASSER (WILEY 2016) OBJECT-ORIENTED
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 informationToday. Book-keeping. Inheritance. Subscribe to sipb-iap-java-students. Slides and code at Interfaces.
Today Book-keeping Inheritance Subscribe to sipb-iap-java-students Interfaces Slides and code at http://sipb.mit.edu/iap/java/ The Object class Problem set 1 released 1 2 So far... Inheritance Basic objects,
More informationOverview. ITI Introduction to Computing II. Interface 1. Problem 1. Problem 1: Array sorting. Problem 1: Array sorting. Problem 1: Array sorting
Overview ITI 1121. Introduction to Computing II Rafael Falcon and Marcel Turcotte (with contributions from R. Holte) Electrical Engineering and Computer Science University of Ottawa Interface Abstract
More informationJava Magistère BFA
Java 101 - Magistère BFA Lesson 3: Object Oriented Programming in Java Stéphane Airiau Université Paris-Dauphine Lesson 3: Object Oriented Programming in Java (Stéphane Airiau) Java 1 Goal : Thou Shalt
More informationMore About Classes CS 1025 Computer Science Fundamentals I Stephen M. Watt University of Western Ontario
More About Classes CS 1025 Computer Science Fundamentals I Stephen M. Watt University of Western Ontario The Story So Far... Classes as collections of fields and methods. Methods can access fields, and
More informationPolymorphism. return a.doublevalue() + b.doublevalue();
Outline Class hierarchy and inheritance Method overriding or overloading, polymorphism Abstract classes Casting and instanceof/getclass Class Object Exception class hierarchy Some Reminders Interfaces
More informationCSE 143 Lecture 22. The Object class; Polymorphism. read slides created by Marty Stepp and Ethan Apter
CSE 143 Lecture 22 The Object class; Polymorphism read 9.2-9.3 slides created by Marty Stepp and Ethan Apter http://www.cs.washington.edu/143/ Class Object All types of objects have a superclass named
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 401 Fall Recitation 6: Inheritance
COMP 401 Fall 2017 Recitation 6: Inheritance Agenda Brief Review of Inheritance Examples of extending existing classes Exercises and Quiz 2 High-level Classes are Abstract Data Types We can define a set
More informationCS 520 Theory and Practice of Software Engineering Fall 2017
CS 520 Theory and Practice of Software Engineering Fall 2017 OO design principles September 14, 2017 Today Code review and (re)design of an MVC application OO design principles Information hiding (and
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 informationThe software crisis. code reuse: The practice of writing program code once and using it in many contexts.
Inheritance The software crisis software engineering: The practice of conceptualizing, designing, developing, documenting, and testing largescale computer programs. Large-scale projects face many issues:
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 informationBig software. code reuse: The practice of writing program code once and using it in many contexts.
Inheritance Big software software engineering: The practice of conceptualizing, designing, developing, documenting, and testing largescale computer programs. Large-scale projects face many issues: getting
More informationProgramming Languages and Techniques (CIS120)
Programming Languages and Techniques (CIS120) Lecture 31 April 3, 2013 Overriding, Equality, and Casts Announcements HW 09 due Tuesday at midnight More informajon about exam 2 available on Friday Unfinished
More informationInheritance. Notes Chapter 6 and AJ Chapters 7 and 8
Inheritance Notes Chapter 6 and AJ Chapters 7 and 8 1 Inheritance you know a lot about an object by knowing its class for example what is a Komondor? http://en.wikipedia.org/wiki/file:komondor_delvin.jpg
More informationCS/ENGRD 2110 FALL Lecture 2: Objects and classes in Java
1 CS/ENGRD 2110 FALL 2018 Lecture 2: Objects and classes in Java http://courses.cs.cornell.edu/cs2110 Homework HW1 2 The answers you handed in at the end of lecture 1 showed mass confusion! Perhaps 80%
More informationProgramming Languages and Techniques (CIS120)
Programming Languages and Techniques (CIS120) Lecture 25 November 1, 2017 Inheritance and Dynamic Dispatch (Chapter 24) Announcements HW7: Chat Client Available Soon Due: Tuesday, November 14 th at 11:59pm
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 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 information