Testing Object-Oriented Software. COMP 4004 Fall Notes Adapted from Dr. A. Williams
|
|
- Constance Watson
- 5 years ago
- Views:
Transcription
1 Testing Object-Oriented Software COMP 4004 Fall 2008 Notes Adapted from Dr. A. Williams Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 1 Testing Object-Oriented Software Relevant characteristics for testing: Encapsulation: access restrictions on variables, methods, classes. Inheritance: code for an object may be in multiple classes in a hierarchy. Polymorphism / dynamic binding: exact version of a method called, or other behaviour, is not known until runtime. Abstract classes: cannot be instantiated and tested directly. Constructors and destructors: creation and termination of objects. Generic classes: Parameterized classes. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 2
2 Additional common OO properties Exceptions Increased number of potential execution paths. How to cause them for testing? State dependent behaviour: Functionality of methods depends on the order methods are called and the data with which they are provided. With encapsulation, state dependencies may not be visible externally. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 3 Encapsulation Restricted class members How to test these methods (for example, using JUnit)? Class TestMe private int somefunction( int someparameter ); protected int tryme( int data ); public int publicmethod( int mydata ); Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 4
3 What about...? Encapsulation Inner classes public Class X private Class TestMe // fields and methods for TestMe // fields and methods for X Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 5 Potential strategies Restricted access to methods: Access methods indirectly: find an access point that is public, that should result in a call to the desired method. Derive a call graph for the class methods, and access the restricted methods indirectly from the nearest public method in the call graph. For languages using a virtual machine (VM): Custom VM that allows JUnit access Access via VM / debugger tools interface Example: JVMTI: Java Virtual Machine Tools Interface. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 6
4 Potential strategies Restricted access to data: Auto-increment values for new objects It may not be possible to predict values in advance, but if two consecutive objects are created, they should have consecutive autoincrement values. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 7 Inheritance Factors: Adding new methods Overriding methods from superclass. may call super() Use of protected fields and methods. Constructors: not inherited may call super() Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 8
5 Inherited and Overridden Methods There are three possibilities for testing methods from the superclass. 1. No retesting of a method in the superclass is needed for the subclass. 2. Test cases that were run for the superclass can be run for the subclass to check the methods in the new context. 3. New test cases are needed for the subclass. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 9 Inherited methods Do the extensions to the class interact with the superclass or simply add additional attributes? If the subclass is purely an extension, retesting of the methods inherited from the superclass, using a subclass object, may not be needed. If the extensions affect the object s state, especially from the superclass point of view, then retesting of the superclass should be done, using an object from the subclass. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 10
6 Overriding methods Is the superclass version of the method called as well? If the superclass version of the method is called, try the test cases from the superclass in the new context. For additional functionality, new tests can be added specifically for the subclass. If not: Functionality that a superclass might expect to be handled by the method may not be present in the subclass version of the method. Test cases for the superclass may no longer be valid. Does the overriding method affect the object s state (especially from the view of the superclass)? If yes: be sure to run all test cases from the superclass. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 11 Example Class 2DPoint int x; int y; 2DPoint( int xvalue, int yvalue ) x = xvalue; y = yvalue; int getx() return x ; int gety() return y ; Class 3DPoint extends 2DPoint int z; 3DPoint( int xvalue, int yvalue, int zvalue ) super( xvalue, yvalue ); z = zvalue; int getz() return z ; In this case, the class 3DPoint provides an additional attribute that is independent of the superclass. Use of the superclass constructor should be checked in class 3DPoint: Check that values are passed to 2DPoint from 3DPoint Superclass methods do not need to be retested. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 12
7 Polymorphism / Dynamic Binding public void amethod( A obj ) // what gets called? obj.testme() If a variable is of type A, and the method testme()is called, there is more than one possible method that could be called. An object that is an instance of any subclass of A can be assigned to a variable of type A. We can only determine the actual method called at runtime. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 13 Polymorphism / Dynamic Binding Method testme() is polymorphic: Class of object A B C where called A A C Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 14
8 Polymorphism / Dynamic Binding Strategy: Try a polymorphic method in (at least) two contexts where different methods will be used. Example: try the method with instances of A and C, to be sure those versions are used. May need to use combinatorial / pairwise approach with combinations of classes. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 15 Abstract classes Abstract classes cannot be instantiated, so objects of this type cannot be created. Methods in abstract classes may or may not be overridden, but they must be accessed from a subclass object. Abstract classes may still have constructors; these would be called from subclasses to do initialization that is expected to be common for all subclasses. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 16
9 Testing Abstract classes If class is abstract, derive a set of instantiations to cover significant cases. If available, can use some concrete classes from application. May need to create a subclass specifically for testing, that adds minimal functionality to be usable. A similar approach can be used for interfaces. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 17 Constructors and Destructors Constructors: Does the language require memory allocation? Was the right amount of memory requested? Was the requested amount available? What if it is not? Are all necessary values initialized? Are superclass constructors called correctly? Destructors: Are all contained objects destroyed as well? Are there resources that need to be cleaned up (network / database connections), etc.? Is the correct amount of memory released? Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 18
10 Issues when testing constructors Is there an invisible default constructor? What if it were to be called by a subclass that doesn t yet exist? Do the constructors need to call superclass constructors explicitly? Are there several constructors? Do they interact with each other? Example: Class Obj int currentsize; Public Obj( ) this( 0 ); // calls other constructor Public Obj( int size ) currentsize = size; //... Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 19 Memory leaks A memory leak is caused when memory is allocated for new objects, and then not released when objects are no longer needed. Some languages (Java, C#, Smalltalk) include automatic garbage collection which attempts to reclaim memory. When an object is no longer accessible, the object is eligible for garbage collection. In languages without automatic garbage collection (C, C++), memory leaks are a concern. Languages with garbage collection are not immune to memory leaks: if the program keeps references that are no longer being used, the garbage collector cannot recover the memory. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 20
11 When do memory leaks occur? Lost references: In C++, an object can no longer be located if there are no references to it, and the memory used by that object is no longer available. Example: Point p1 = new Point( 2, 1 ); Point p2 = new Point( 4, 3 ); p1 = p2; // reference to original p1 lost Object de-allocation: An object that creates other objects has to be sure to free those objects when it is itself de-allocated. What about collections? An object has to free exactly the same amount of memory as when it was allocated. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 21 Symptoms of memory leaks As memory is slowly lost, the amount of memory available for new objects will gradually shrink. Eventually this could be after weeks or months of continuous operation there isn t enough memory to fulfill a new request, and an out of memory error occurs in a constructor or when memory is allocated for an array. When the system is restarted, it will likely appear to run correctly. Memory leaks are difficult to detect, and to isolate. Specialized tools are available: Purify, from IBM/Rational Valgrind (open source, for Linux OS) Mozilla memory tools suite Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 22
12 Generic Classes Classes with one or more parameters. Often used for collections. Example: The Java class HashMap<K,V>. Class has two parameters: K: key type for the map V: value type for the map. Purpose of the class is to keep a collection of (key,value) pairs. Method in the class: Public V get( K key ); Other features: Type-restricted parameters: AClass<T, S extends T> Wild card parameters: AClass<? extends Shape> // any type Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 23 Testing Generic Classes Generic classes are similar to abstract classes; they cannot be instantiated on their own Try instantiating the class with representative classes as the parameter. Ones that are expected to be used. Class Object. Try a subclass of a parameter that has an extends clause. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 24
13 Classes with state If objects created from the class have state, build a state machine model of the class behaviour, and derive tests from it. Minimal coverage: a transition tour. Repeat state-based tests for subclasses. New tests specifically for subclasses may need to be added if there are additional states. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 25 Exceptions The use of exceptions can vastly increase the number of potential control flow paths. Exception handling can be chained. A calls B. B calls C. C throws an exception. B does not catch the exception In Java, method B would need a throws clause, even if the exception is not thrown within B. A catches the exception. Should all paths and / or chains be tested? Chained exceptions that pass through with no effect (such as B above) are usually not worth testing. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 26
14 Exceptions If exceptions are thrown within the class, try to arrange for them to be caused. This can be difficult in some cases. Effort needed to create the exception situation must be balanced against risk and the reliability of the test case to cause the exception on demand. If exceptions are caught in the class, check that the handling behaviour is appropriate. Safety-critical systems need careful testing of exception handling. Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 27 Recovery from Exceptions When an exception is caught, be careful to ensure that the appropriate action is taken. Does the exception result in a graceful shutdown Network / database connections closed. Is there an attempt to restore the system to a usable state? Is the exception brought to the attention of a user? Dr. A. Williams, Fall 2008 Software Quality Assurance Lec 9 28
CMSC 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 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, and Polymorphism.
Inheritance and Polymorphism by Yukong Zhang Object-oriented programming languages are the most widely used modern programming languages. They model programming based on objects which are very close to
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 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 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 informationUNIT 3 ARRAYS, RECURSION, AND COMPLEXITY CHAPTER 11 CLASSES CONTINUED
UNIT 3 ARRAYS, RECURSION, AND COMPLEXITY CHAPTER 11 CLASSES CONTINUED EXERCISE 11.1 1. static public final int DEFAULT_NUM_SCORES = 3; 2. Java allocates a separate set of memory cells in each instance
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 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 informationAP COMPUTER SCIENCE JAVA CONCEPTS IV: RESERVED WORDS
AP COMPUTER SCIENCE JAVA CONCEPTS IV: RESERVED WORDS PAUL L. BAILEY Abstract. This documents amalgamates various descriptions found on the internet, mostly from Oracle or Wikipedia. Very little of this
More informationEMBEDDED SYSTEMS PROGRAMMING OO Basics
EMBEDDED SYSTEMS PROGRAMMING 2014-15 OO Basics CLASS, METHOD, OBJECT... Class: abstract description of a concept Object: concrete realization of a concept. An object is an instance of a class Members Method:
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 informationG Programming Languages Spring 2010 Lecture 9. Robert Grimm, New York University
G22.2110-001 Programming Languages Spring 2010 Lecture 9 Robert Grimm, New York University 1 Review Last week Modules 2 Outline Classes Encapsulation and Inheritance Initialization and Finalization Dynamic
More informationOutline. Java Models for variables Types and type checking, type safety Interpretation vs. compilation. Reasoning about code. CSCI 2600 Spring
Java Outline Java Models for variables Types and type checking, type safety Interpretation vs. compilation Reasoning about code CSCI 2600 Spring 2017 2 Java Java is a successor to a number of languages,
More informationWritten by John Bell for CS 342, Spring 2018
Advanced OO Concepts Written by John Bell for CS 342, Spring 2018 Based on chapter 3 of The Object-Oriented Thought Process by Matt Weisfeld, with additional material from other sources. Constructors Constructors
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 informationDOWNLOAD PDF CORE JAVA APTITUDE QUESTIONS AND ANSWERS
Chapter 1 : Chapter-wise Java Multiple Choice Questions and Answers Interview MCQs Java Programming questions and answers with explanation for interview, competitive examination and entrance test. Fully
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 informationOOPS Viva Questions. Object is termed as an instance of a class, and it has its own state, behavior and identity.
OOPS Viva Questions 1. What is OOPS? OOPS is abbreviated as Object Oriented Programming system in which programs are considered as a collection of objects. Each object is nothing but an instance of a class.
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 informationCS250 Intro to CS II. Spring CS250 - Intro to CS II 1
CS250 Intro to CS II Spring 2017 CS250 - Intro to CS II 1 Topics Virtual Functions Pure Virtual Functions Abstract Classes Concrete Classes Binding Time, Static Binding, Dynamic Binding Overriding vs Redefining
More informationChapter 12. OOP: Creating Object-Oriented Programs The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill
Chapter 12 OOP: Creating Object-Oriented Programs McGraw-Hill 2010 The McGraw-Hill Companies, Inc. All rights reserved. Chapter Objectives - 1 Use object-oriented terminology correctly Create a two-tier
More informationData Abstraction. Hwansoo Han
Data Abstraction Hwansoo Han Data Abstraction Data abstraction s roots can be found in Simula67 An abstract data type (ADT) is defined In terms of the operations that it supports (i.e., that can be performed
More informationG Programming Languages - Fall 2012
G22.2110-003 Programming Languages - Fall 2012 Lecture 12 Thomas Wies New York University Review Last lecture Modules Outline Classes Encapsulation and Inheritance Initialization and Finalization Dynamic
More informationWhat about Object-Oriented Languages?
What about Object-Oriented Languages? What is an OOL? A language that supports object-oriented programming How does an OOL differ from an ALL? (ALGOL-Like Language) Data-centric name scopes for values
More informationCompaq Interview Questions And Answers
Part A: Q1. What are the difference between java and C++? Java adopts byte code whereas C++ does not C++ supports destructor whereas java does not support. Multiple inheritance possible in C++ but not
More informationCS Internet programming Unit- I Part - A 1 Define Java. 2. What is a Class? 3. What is an Object? 4. What is an Instance?
CS6501 - Internet programming Unit- I Part - A 1 Define Java. Java is a programming language expressly designed for use in the distributed environment of the Internet. It was designed to have the "look
More informationJava. Classes 3/3/2014. Summary: Chapters 1 to 10. Java (2)
Summary: Chapters 1 to 10 Sharma Chakravarthy Information Technology Laboratory (IT Lab) Computer Science and Engineering Department The University of Texas at Arlington, Arlington, TX 76019 Email: sharma@cse.uta.edu
More informationCOMP200 INTERFACES. OOP using Java, from slides by Shayan Javed
1 1 COMP200 INTERFACES OOP using Java, from slides by Shayan Javed Interfaces 2 ANIMAL picture food sleep() roam() makenoise() eat() 3 ANIMAL picture food sleep() roam() makenoise() eat() 4 roam() FELINE
More informationInheritance. Inheritance allows the following two changes in derived class: 1. add new members; 2. override existing (in base class) methods.
Inheritance Inheritance is the act of deriving a new class from an existing one. Inheritance allows us to extend the functionality of the object. The new class automatically contains some or all methods
More informationIntroduction to Object- Oriented Programming
Introduction to Object- Oriented Programming Reusing this material This work is licensed under a Creative Commons Attribution- NonCommercial-ShareAlike 4.0 International License. http://creativecommons.org/licenses/by-nc-sa/4.0/deed.en_us
More informationFundamentals of Object Oriented Programming
INDIAN INSTITUTE OF TECHNOLOGY ROORKEE Fundamentals of Object Oriented Programming CSN- 103 Dr. R. Balasubramanian Associate Professor Department of Computer Science and Engineering Indian Institute of
More informationWeiss Chapter 1 terminology (parenthesized numbers are page numbers)
Weiss Chapter 1 terminology (parenthesized numbers are page numbers) assignment operators In Java, used to alter the value of a variable. These operators include =, +=, -=, *=, and /=. (9) autoincrement
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 informationDesign issues for objectoriented. languages. Objects-only "pure" language vs mixed. Are subclasses subtypes of the superclass?
Encapsulation Encapsulation grouping of subprograms and the data they manipulate Information hiding abstract data types type definition is hidden from the user variables of the type can be declared variables
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 information1B1b Inheritance. Inheritance. Agenda. Subclass and Superclass. Superclass. Generalisation & Specialisation. Shapes and Squares. 1B1b Lecture Slides
1B1b Inheritance Agenda Introduction to inheritance. How Java supports inheritance. Inheritance is a key feature of object-oriented oriented programming. 1 2 Inheritance Models the kind-of or specialisation-of
More informationData Structures (list, dictionary, tuples, sets, strings)
Data Structures (list, dictionary, tuples, sets, strings) Lists are enclosed in brackets: l = [1, 2, "a"] (access by index, is mutable sequence) Tuples are enclosed in parentheses: t = (1, 2, "a") (access
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 informationObject-Oriented Programming
Object-Oriented Programming 1. What is object-oriented programming (OOP)? OOP is a technique to develop logical modules, such as classes that contain properties, methods, fields, and events. An object
More informationPieter van den Hombergh Thijs Dorssers Stefan Sobek. January 11, 2018
Inheritance and Inheritance and Pieter van den Hombergh Thijs Dorssers Stefan Sobek Java Inheritance Example I Visibility peekabo Constructors Fontys Hogeschool voor Techniek en Logistiek January 11, 2018
More informationC++ Inheritance and Encapsulation
C++ Inheritance and Encapsulation Private and Protected members Inheritance Type Public Inheritance Private Inheritance Protected Inheritance Special method inheritance 1 Private Members Private members
More informationOBJECT ORIENTED PROGRAMMING USING C++ CSCI Object Oriented Analysis and Design By Manali Torpe
OBJECT ORIENTED PROGRAMMING USING C++ CSCI 5448- Object Oriented Analysis and Design By Manali Torpe Fundamentals of OOP Class Object Encapsulation Abstraction Inheritance Polymorphism Reusability C++
More information15CS45 : OBJECT ORIENTED CONCEPTS
15CS45 : OBJECT ORIENTED CONCEPTS QUESTION BANK: What do you know about Java? What are the supported platforms by Java Programming Language? List any five features of Java? Why is Java Architectural Neutral?
More informationInheritance (Deitel chapter 9)
Inheritance (Deitel chapter 9) 1 2 Plan Introduction Superclasses and Subclasses protected Members Constructors and Finalizers in Subclasses Software Engineering with Inheritance 3 Introduction Inheritance
More informationChapter 4.!Data Abstraction: The Walls! 2011 Pearson Addison-Wesley. All rights reserved 4-1
Chapter 4!Data Abstraction: The Walls! 2011 Pearson Addison-Wesley. All rights reserved 4-1 2015-09-29 11:44:25 1/45 Chapter-04.pdf (#4) bubblesort(int[] a) { int last = a.length - 1; while (last > 0)
More information(800) Toll Free (804) Fax Introduction to Java and Enterprise Java using Eclipse IDE Duration: 5 days
Course Description This course introduces the Java programming language and how to develop Java applications using Eclipse 3.0. Students learn the syntax of the Java programming language, object-oriented
More informationData Abstraction: The Walls
Chapter 4 Data Abstraction: The Walls 2011 Pearson Addison-Wesley. All rights reserved 4-1 Abstract Data Types Modularity Keeps the complexity of a large program manageable by systematically controlling
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 informationCS 221 Review. Mason Vail
CS 221 Review Mason Vail Inheritance (1) Every class - except the Object class - directly inherits from one parent class. Object is the only class with no parent. If a class does not declare a parent using
More informationIT101. Inheritance, Encapsulation, Polymorphism and Constructors
IT101 Inheritance, Encapsulation, Polymorphism and Constructors OOP Advantages and Concepts What are OOP s claims to fame? Better suited for team development Facilitates utilizing and creating reusable
More informationObject-Oriented Programming (OOP) Fundamental Principles of OOP
Object-Oriented Programming (OOP) O b j e c t O r i e n t e d P r o g r a m m i n g 1 Object-oriented programming is the successor of procedural programming. The problem with procedural programming is
More informationCPS 506 Comparative Programming Languages. Programming Language
CPS 506 Comparative Programming Languages Object-Oriented Oriented Programming Language Paradigm Introduction Topics Object-Oriented Programming Design Issues for Object-Oriented Oriented Languages Support
More informationVIRTUAL FUNCTIONS Chapter 10
1 VIRTUAL FUNCTIONS Chapter 10 OBJECTIVES Polymorphism in C++ Pointers to derived classes Important point on inheritance Introduction to virtual functions Virtual destructors More about virtual functions
More informationCore Java - SCJP. Q2Technologies, Rajajinagar. Course content
Core Java - SCJP Course content NOTE: For exam objectives refer to the SCJP 1.6 objectives. 1. Declarations and Access Control Java Refresher Identifiers & JavaBeans Legal Identifiers. Sun's Java Code
More informationCS313D: ADVANCED PROGRAMMING LANGUAGE
CS313D: ADVANCED PROGRAMMING LANGUAGE Computer Science department Lecture 6 : Abstraction Lecture Contents 2 Abstract classes Abstract methods Case study: Polymorphic processing Sealed methods & classes
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 informationCS 6456 OBJCET ORIENTED PROGRAMMING IV SEMESTER/EEE
CS 6456 OBJCET ORIENTED PROGRAMMING IV SEMESTER/EEE PART A UNIT I 1. Differentiate object oriented programming from procedure oriented programming. 2. Define abstraction and encapsulation. 3. Differentiate
More informationCS 11 java track: lecture 3
CS 11 java track: lecture 3 This week: documentation (javadoc) exception handling more on object-oriented programming (OOP) inheritance and polymorphism abstract classes and interfaces graphical user interfaces
More informationCOMP322 - Introduction to C++ Lecture 10 - Overloading Operators and Exceptions
COMP322 - Introduction to C++ Lecture 10 - Overloading Operators and Exceptions Dan Pomerantz School of Computer Science 19 March 2012 Overloading operators in classes It is useful sometimes to define
More informationObject-Oriented Concepts and Principles (Adapted from Dr. Osman Balci)
Object-Oriented Concepts and Principles (Adapted from Dr. Osman Balci) Sung Hee Park Department of Mathematics and Computer Science Virginia State University September 18, 2012 The Object-Oriented Paradigm
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 informationException Handling Introduction. Error-Prevention Tip 13.1 OBJECTIVES
1 2 13 Exception Handling It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something. Franklin Delano Roosevelt O throw away the worser
More informationI BCS-031 BACHELOR OF COMPUTER APPLICATIONS (BCA) (Revised) Term-End Examination. June, 2015 BCS-031 : PROGRAMMING IN C ++
No. of Printed Pages : 3 I BCS-031 BACHELOR OF COMPUTER APPLICATIONS (BCA) (Revised) Term-End Examination 05723. June, 2015 BCS-031 : PROGRAMMING IN C ++ Time : 3 hours Maximum Marks : 100 (Weightage 75%)
More informationCSE 452: Programming Languages. Previous Lecture. From ADTs to OOP. Data Abstraction and Object-Orientation
CSE 452: Programming Languages Data Abstraction and Object-Orientation Previous Lecture Abstraction Abstraction is the elimination of the irrelevant and the amplification of the essential Robert C Martin
More informationIntroduction to Java Written by John Bell for CS 342, Spring 2018
Introduction to Java Written by John Bell for CS 342, Spring 2018 Based on chapters 1 to 6 of Learning Java by Patrick Niemeyer and Daniel Leuck, with additional material from other sources. History I
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 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 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 informationOverview of OOP. Dr. Zhang COSC 1436 Summer, /18/2017
Overview of OOP Dr. Zhang COSC 1436 Summer, 2017 7/18/2017 Review Data Structures (list, dictionary, tuples, sets, strings) Lists are enclosed in square brackets: l = [1, 2, "a"] (access by index, is mutable
More informationOOPs Concepts. 1. Data Hiding 2. Encapsulation 3. Abstraction 4. Is-A Relationship 5. Method Signature 6. Polymorphism 7. Constructors 8.
OOPs Concepts 1. Data Hiding 2. Encapsulation 3. Abstraction 4. Is-A Relationship 5. Method Signature 6. Polymorphism 7. Constructors 8. Type Casting Let us discuss them in detail: 1. Data Hiding: Every
More informationAssoc. Prof. Marenglen Biba. (C) 2010 Pearson Education, Inc. All rights reserved.
Assoc. Prof. Marenglen Biba Exception handling Exception an indication of a problem that occurs during a program s execution. The name exception implies that the problem occurs infrequently. With exception
More informationChapter 13 Object Oriented Programming. Copyright 2006 The McGraw-Hill Companies, Inc.
Chapter 13 Object Oriented Programming Contents 13.1 Prelude: Abstract Data Types 13.2 The Object Model 13.4 Java 13.1 Prelude: Abstract Data Types Imperative programming paradigm Algorithms + Data Structures
More informationCS304- Object Oriented Programming LATEST SOLVED MCQS FROM FINALTERM PAPERS. MC
CS304- Object Oriented Programming LATEST SOLVED MCQS FROM FINALTERM PAPERS JAN 28,2011 MC100401285 Moaaz.pk@gmail.com Mc100401285@gmail.com PSMD01 FINALTERM EXAMINATION 14 Feb, 2011 CS304- Object Oriented
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 informationPieter van den Hombergh Thijs Dorssers Stefan Sobek. February 10, 2017
Inheritance and Inheritance and Pieter van den Hombergh Thijs Dorssers Stefan Sobek Fontys Hogeschool voor Techniek en Logistiek February 10, 2017 /FHTenL Inheritance and February 10, 2017 1/45 Topics
More information(12-1) OOP: Polymorphism in C++ D & D Chapter 12. Instructor - Andrew S. O Fallon CptS 122 (April 3, 2019) Washington State University
(12-1) OOP: Polymorphism in C++ D & D Chapter 12 Instructor - Andrew S. O Fallon CptS 122 (April 3, 2019) Washington State University Key Concepts Polymorphism virtual functions Virtual function tables
More informationInheritance. Benefits of Java s Inheritance. 1. Reusability of code 2. Code Sharing 3. Consistency in using an interface. Classes
Inheritance Inheritance is the mechanism of deriving new class from old one, old class is knows as superclass and new class is known as subclass. The subclass inherits all of its instances variables and
More informationCPSC 427: Object-Oriented Programming
CPSC 427: Object-Oriented Programming Michael J. Fischer Lecture 22 November 28, 2016 CPSC 427, Lecture 22 1/43 Exceptions (continued) Code Reuse Linear Containers Ordered Containers Multiple Inheritance
More informationCSCI-142 Exam 1 Review September 25, 2016 Presented by the RIT Computer Science Community
CSCI-12 Exam 1 Review September 25, 2016 Presented by the RIT Computer Science Community http://csc.cs.rit.edu 1. Provide a detailed explanation of what the following code does: 1 public boolean checkstring
More informationAtelier Java - J1. Marwan Burelle. EPITA Première Année Cycle Ingénieur.
marwan.burelle@lse.epita.fr http://wiki-prog.kh405.net Plan 1 2 Plan 3 4 Plan 1 2 3 4 A Bit of History JAVA was created in 1991 by James Gosling of SUN. The first public implementation (v1.0) in 1995.
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 informationJAVA MOCK TEST JAVA MOCK TEST II
http://www.tutorialspoint.com JAVA MOCK TEST Copyright tutorialspoint.com This section presents you various set of Mock Tests related to Java Framework. You can download these sample mock tests at your
More informationPolymorphism. Object Orientated Programming in Java. Benjamin Kenwright
Polymorphism Object Orientated Programming in Java Benjamin Kenwright Quizzes/Labs Every single person should have done Quiz 00 Introduction Quiz 01 - Java Basics Every single person should have at least
More informationCS11 Introduction to C++ Fall Lecture 7
CS11 Introduction to C++ Fall 2012-2013 Lecture 7 Computer Strategy Game n Want to write a turn-based strategy game for the computer n Need different kinds of units for the game Different capabilities,
More informationWhat property of a C# array indicates its allocated size? What keyword in the base class allows a method to be polymorphic?
What property of a C# array indicates its allocated size? a. Size b. Count c. Length What property of a C# array indicates its allocated size? a. Size b. Count c. Length What keyword in the base class
More informationMore on Objects in JAVA TM
More on Objects in JAVA TM Inheritance : Definition: A subclass is a class that extends another class. A subclass inherits state and behavior from all of its ancestors. The term superclass refers to a
More informationLecture 13: Object orientation. Object oriented programming. Introduction. Object oriented programming. OO and ADT:s. Introduction
Lecture 13: Object orientation Object oriented programming Introduction, types of OO languages Key concepts: Encapsulation, Inheritance, Dynamic binding & polymorphism Other design issues Smalltalk OO
More informationGet Unique study materials from
Downloaded from www.rejinpaul.com VALLIAMMAI ENGNIEERING COLLEGE SRM Nagar, Kattankulathur 603203. DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING Year & Semester : IV Section : EEE - 1 & 2 Subject Code
More information1 Shyam sir JAVA Notes
1 Shyam sir JAVA Notes 1. What is the most important feature of Java? Java is a platform independent language. 2. What do you mean by platform independence? Platform independence means that we can write
More informationShort Notes of CS201
#includes: Short Notes of CS201 The #include directive instructs the preprocessor to read and include a file into a source code file. The file name is typically enclosed with < and > if the file is a system
More informationInheritance and Polymorphism
Division of Mathematics and Computer Science Maryville College Outline Inheritance 1 Inheritance 2 3 Outline Inheritance 1 Inheritance 2 3 The "is-a" Relationship The "is-a" Relationship Object classification
More informationChapter 11. Categories of languages that support OOP: 1. OOP support is added to an existing language
Categories of languages that support OOP: 1. OOP support is added to an existing language - C++ (also supports procedural and dataoriented programming) - Ada 95 (also supports procedural and dataoriented
More informationJava Fundamentals (II)
Chair of Software Engineering Languages in Depth Series: Java Programming Prof. Dr. Bertrand Meyer Java Fundamentals (II) Marco Piccioni static imports Introduced in 5.0 Imported static members of a class
More informationType Hierarchy. Lecture 6: OOP, autumn 2003
Type Hierarchy Lecture 6: OOP, autumn 2003 The idea Many types have common behavior => type families share common behavior organized into a hierarchy Most common on the top - supertypes Most specific at
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 informationInheritance and Polymorphism
Object Oriented Programming Designed and Presented by Dr. Ayman Elshenawy Elsefy Dept. of Systems & Computer Eng.. Al-Azhar University Website: eaymanelshenawy.wordpress.com Email : eaymanelshenawy@azhar.edu.eg
More informationCOMP6771 Advanced C++ Programming
1.... COMP6771 Advanced C++ Programming Week 5 Part One: Exception Handling 2016 www.cse.unsw.edu.au/ cs6771 2.... Memory Management & Exception Handling.1 Part I: Exception Handling Exception objects
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 informationCS201 - Introduction to Programming Glossary By
CS201 - Introduction to Programming Glossary By #include : The #include directive instructs the preprocessor to read and include a file into a source code file. The file name is typically enclosed with
More information