Object Oriented Programming Exception Handling
|
|
- Bernice Waters
- 6 years ago
- Views:
Transcription
1 Object Oriented Programming Exception Handling Budditha Hettige Department of Computer Science
2 Programming Errors Types Syntax Errors Logical Errors Runtime Errors Syntax Errors Error in the syntax of a sequence of characters or tokens that is intended to be written in a particular programming language All syntax errors can be reliably detected until run-time Many Syntax errors can be detected at compile-time 2
3 Common Java syntax errors Capitalization of key words Line xx: class or interface declaration expected Writing a string over a new line Line xx: ';' expected Forgetting to import a package 3
4 Logical Errors Errors that indicate the logic used when coding the program failed to solve the problem You do not get error messages with logic errors Your only clue to the existence of logic errors is the production of wrong solutions Debugging is a way to solve logical errors Insert breakpoint(s) Debug your code Check variable values at run time 4
5 Common Logic Errors in Java Using a variable before it is given a value int x; x = x + 1; System.out.println("X = " + x); Misplaced Semi-colon (usually with a loop or if statement) if ( x > y) ; System.out.println("X is bigger"); Confusing the equivalence operator == with the assignment operator = 5
6 Runtime Errors low-level errors dereference of a null pointer out-of-bounds array access divide by zero attempt to open a non-existent file for reading bad cast (e.g., casting an Object that is actually a Boolean to Integer) higher-level call to Stack's "pop" method for an empty stack call to "factorial" function with a negative number call to List's nextelement method when hasmoreelements is false 6
7 Runtime Errors contd.. Errors can arise due to User error providing a bad file name or a poorly formatted input file Enter invalid input (Type) Programmer error These errors should be detected as early as possible to provide good feedback. 7
8 Exceptions can occur at many levels Hardware/operating system level. Arithmetic exceptions; divide by 0, under/overflow. Memory access violations; segfault, stack over/underflow. Language level. Type conversion; illegal values, improper casts. Bounds violations; illegal array indices. Bad references; null pointers. Program level. User defined exceptions. 8
9 Way to handle errors Write an error message and quit. This doesn't provide any recovery Return a special value to indicate that an error occurred calling code check for an error. This can reduce the efficiency of the code Use a reference parameter or a global variable to hold an error code Use exceptions. This seems to be the method of choice for modern programming languages. 9
10 What Is an Exception? An exception is an event that occurs during the execution of a program that disrupts the normal flow of instructions. Example Divide by zero errors Accessing the elements of an array beyond its range Invalid input Hard disk crash Opening a non-existent file Heap memory exhausted 10
11 Example class DivByZero public static void main(string args[]) System.out.println(3/0); System.out.println( Pls. print me. ); Error Message Exception in thread "main" java.lang.arithmeticexception: / by zero at DivByZero.main(DivByZero.java:3) Divide by zero Where the error is occurred 11
12 Default exception handler (Java) 1. Provided by Java runtime 2. Prints out exception description 3. Prints the stack trace 4. Hierarchy of methods where the exception occurred 5. Causes the program to terminate Exception in thread "main" java.lang.arithmeticexception: / by zero at DivByZero.main(DivByZero.java:3) 12
13 When an Exception Occurs? When an exception occurs within a method, the method creates an exception object and hands it off to the runtime system Creating an exception object and handing it to the runtime system is called throwing an exception Exception object contains information about the error, including its type and the state of the program when the error occurred Exception in thread "main" java.lang.arithmeticexception: / by zero at DivByZero.main(DivByZero.java:3) 13
14 Java Exception Handling A method can duck any exceptions thrown within it, thereby allowing a method farther up the call stack to catch it. Hence, only the methods that care about errors have to worry about detecting errors Any checked exceptions that can be thrown within a method must be specified in its throws clause 14
15 Java exception hierarchy 15
16 Catching Exceptions try <code to be monitored for exceptions> catch (<ExceptionType1> <ObjName>) <handler if ExceptionType1 occurs>... catch (<ExceptionTypeN> <ObjName>) <handler if ExceptionTypeN occurs> 16
17 Example 17
18 Multiple catch 18
19 How try and catch works? NO Match Try Catch Catch Statement after the last catch Leaves the method 19
20 Example 1. Execute This 2. Go to this catch() 3. Execute This 20
21 Catching Exceptions with finally Syntax: try <code to be monitored for exceptions> catch (<ExceptionType1> <ObjName>) <handler if ExceptionType1 occurs>... finally <code to be executed before the try block ends> 21
22 Catching Exceptions the finally Keyword Block of code is always executed despite of different scenarios: Forced exit occurs using a return, a continue or a break statement Normal completion Caught exception thrown Exception was thrown and caught in the method Uncaught exception thrown Exception thrown was not specified in any catch block in the method 22
23 How try and catch finaly works? Try Catch Catch NO Match Finally() Statement after the last catch 23
24 Throwing Exceptions Java allows you to throw exceptions (generate exceptions) throw <exception object>; An exception you throw is an object You have to create an exception object in the same way you create any other object Example: throw new ArithmeticException( testing... ); 24
CSC System Development with Java. Exception Handling. Department of Statistics and Computer Science. Budditha Hettige
CSC 308 2.0 System Development with Java Exception Handling Department of Statistics and Computer Science 1 2 Errors Errors can be categorized as several ways; Syntax Errors Logical Errors Runtime Errors
More informationLe L c e t c ur u e e 5 To T p o i p c i s c t o o b e b e co c v o e v r e ed e Exception Handling
Course Name: Advanced Java Lecture 5 Topics to be covered Exception Handling Exception HandlingHandlingIntroduction An exception is an abnormal condition that arises in a code sequence at run time A Java
More informationDownload link: Java Exception Handling
What is an Exception? Java Exception Handling Error that occurs during runtime Exceptional event Cause normal program flow to be disrupted Java Exception Examples 1. Divide by zero errors 2. Accessing
More informationAdministration. Exceptions. Leftovers. Agenda. When Things Go Wrong. Handling Errors. CS 99 Summer 2000 Michael Clarkson Lecture 11
Administration Exceptions CS 99 Summer 2000 Michael Clarkson Lecture 11 Lab 10 due tomorrow No lab tomorrow Work on final projects Remaining office hours Rick: today 2-3 Michael: Thursday 10-noon, Monday
More informationException Handling. Sometimes when the computer tries to execute a statement something goes wrong:
Exception Handling Run-time errors The exception concept Throwing exceptions Handling exceptions Declaring exceptions Creating your own exception Ariel Shamir 1 Run-time Errors Sometimes when the computer
More informationECE 122. Engineering Problem Solving with Java
ECE 122 Engineering Problem Solving with Java Lecture 24 Exceptions Overview Problem: Can we detect run-time errors and take corrective action? Try-catch Test for a variety of different program situations
More informationException Handling. Run-time Errors. Methods Failure. Sometimes when the computer tries to execute a statement something goes wrong:
Exception Handling Run-time errors The exception concept Throwing exceptions Handling exceptions Declaring exceptions Creating your own exception 22 November 2007 Ariel Shamir 1 Run-time Errors Sometimes
More informationObject Oriented Programming
Object Oriented Programming Java lecture (10.1) Exception Handling 1 Outline Exception Handling Mechanisms Exception handling fundamentals Exception Types Uncaught exceptions Try and catch Multiple catch
More informationBBM 102 Introduction to Programming II Spring Exceptions
BBM 102 Introduction to Programming II Spring 2018 Exceptions 1 Today What is an exception? What is exception handling? Keywords of exception handling try catch finally Throwing exceptions throw Custom
More informationLecture 20. Java Exceptional Event Handling. Dr. Martin O Connor CA166
Lecture 20 Java Exceptional Event Handling Dr. Martin O Connor CA166 www.computing.dcu.ie/~moconnor Topics What is an Exception? Exception Handler Catch or Specify Requirement Three Kinds of Exceptions
More informationProgramming II (CS300)
1 Programming II (CS300) Chapter 04: Exception Handling MOUNA KACEM mouna@cs.wisc.edu Spring 2018 Creating Classes 2 Introduction Exception Handling Common Exceptions Exceptions with Methods Assertions
More informationProgram Correctness and Efficiency. Chapter 2
Program Correctness and Efficiency Chapter 2 Chapter Objectives To understand the differences between the three categories of program errors To understand the effect of an uncaught exception and why you
More informationException Handling. Chapter 11. Outline. Example: The Quotient app What Are Exceptions? Java By Abstraction Chapter 11
Outline Chapter 11 Exception Handling 11.1 What are Exceptions? 11.1.1 Exception Handling 11.1.2 The Delegation Model 11.2 Java's Exception Constructs 11.2.1 The Basic -catch Construct 11.2.2 Handling
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 informationProgramming II (CS300)
1 Programming II (CS300) Chapter 04: Exception Handling MOUNA KACEM mouna@cs.wisc.edu Fall 2018 Creating Classes 2 Introduction Exception Handling Common Exceptions Exceptions with Methods Assertions and
More informationException-Handling Overview
م.عبد الغني أبوجبل Exception Handling No matter how good a programmer you are, you cannot control everything. Things can go wrong. Very wrong. When you write a risky method, you need code to handle the
More informationObject oriented programming. Instructor: Masoud Asghari Web page: Ch: 7
Object oriented programming Instructor: Masoud Asghari Web page: http://www.masses.ir/lectures/oops2017sut Ch: 7 1 In this slide We follow: https://docs.oracle.com/javase/tutorial/index.html Trail: Essential
More informationC16b: Exception Handling
CISC 3120 C16b: Exception Handling Hui Chen Department of Computer & Information Science CUNY Brooklyn College 3/28/2018 CUNY Brooklyn College 1 Outline Exceptions Catch and handle exceptions (try/catch)
More informationException Handling in Java. An Exception is a compile time / runtime error that breaks off the
Description Exception Handling in Java An Exception is a compile time / runtime error that breaks off the program s execution flow. These exceptions are accompanied with a system generated error message.
More informationExceptions - Example. Exceptions - Example
- Example //precondition: x >= 0 public void sqrt(double x) double root; if (x < 0.0) //What to do? else //compute the square root of x return root; 1 - Example //precondition: x >= 0 public void sqrt(double
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 informationBBM 102 Introduction to Programming II Spring 2017
BBM 102 Introduction to Programming II Spring 2017 Exceptions Instructors: Ayça Tarhan, Fuat Akal, Gönenç Ercan, Vahid Garousi Today What is an exception? What is exception handling? Keywords of exception
More informationData Structure. Recitation IV
Data Structure Recitation IV Topic Java Generics Java error handling Stack Lab 2 Java Generics The following code snippet without generics requires casting: List list = new ArrayList(); list.add("hello");
More informationReminder. Topics CSE What Are Exceptions?! Lecture 11 Exception Handling
Reminder CSE 1720 Lecture 11 Exception Handling Midterm Exam" Thursday, Feb 16, 10-11:30" CLH J Curtis Lecture Hall, Room J! will cover all material up to and including Tues Feb 14th! Tues, Feb 7 topic:
More informationStd 12 Lesson-10 Exception Handling in Java ( 1
Ch-10 : Exception Handling in Java 1) It is usually understood that a compiled program is error free and will always successfully. (a) complete (b) execute (c) perform (d) accomplish 2) In few cases a
More informationIntroduction to Programming Using Java (98-388)
Introduction to Programming Using Java (98-388) Understand Java fundamentals Describe the use of main in a Java application Signature of main, why it is static; how to consume an instance of your own class;
More informationExceptions. Computer Science and Engineering College of Engineering The Ohio State University. Lecture 15
s Computer Science and Engineering College of Engineering The Ohio State University Lecture 15 Throwable Hierarchy extends implements Throwable Serializable Internal problems or resource exhaustion within
More informationCS115. Chapter 17 Exception Handling. Prof. Joe X. Zhou Department of Computer Science. To know what is exception and what is exception handling
CS115 Pi Principles i of fcomputer Science Chapter 17 Exception Handling Prof. Joe X. Zhou Department of Computer Science CS115 ExceptionHandling.1 Objectives in Exception Handling To know what is exception
More informationIntroduction. Exceptions: An OO Way for Handling Errors. Common Runtime Errors. Error Handling. Without Error Handling Example 1
Exceptions: An OO Way for Handling Errors Introduction Rarely does a program runs successfully at its very first attempt. It is common to make mistakes while developing as well as typing a program. Such
More informationComputer Components. Software{ User Programs. Operating System. Hardware
Computer Components Software{ User Programs Operating System Hardware What are Programs? Programs provide instructions for computers Similar to giving directions to a person who is trying to get from point
More informationCSCI 261 Computer Science II
CSCI 261 Computer Science II Department of Mathematics and Computer Science Lecture 2 Exception Handling New Topic: Exceptions in Java You should now be familiar with: Advanced object-oriented design -
More informationCSC 1214: Object-Oriented Programming
CSC 1214: Object-Oriented Programming J. Kizito Makerere University e-mail: jkizito@cis.mak.ac.ug www: http://serval.ug/~jona materials: http://serval.ug/~jona/materials/csc1214 e-learning environment:
More informationExceptions. What exceptional things might our programs run in to?
Exceptions What exceptional things might our programs run in to? Exceptions do occur Whenever we deal with programs, we deal with computers and users. Whenever we deal with computers, we know things don
More informationSchool of Informatics, University of Edinburgh
CS1Ah Lecture Note 29 Streams and Exceptions We saw back in Lecture Note 9 how to design and implement our own Java classes. An object such as a Student4 object contains related fields such as surname,
More informationCOE318 Lecture Notes Week 10 (Nov 7, 2011)
COE318 Software Systems Lecture Notes: Week 10 1 of 5 COE318 Lecture Notes Week 10 (Nov 7, 2011) Topics More about exceptions References Head First Java: Chapter 11 (Risky Behavior) The Java Tutorial:
More informationJava Errors and Exceptions. Because Murphy s Law never fails
Java Errors and Exceptions Because Murphy s Law never fails 1 Java is the most distressing thing to hit computing since MS-DOS. Alan Kay 2 Corresponding Book Sections Pearson Custom Computer Science: Chapter
More informationDebugging and Handling Exceptions
12 Debugging and Handling Exceptions C# Programming: From Problem Analysis to Program Design C# Programming: From Problem Analysis to Program Design 1 4th Edition Chapter Objectives Learn about exceptions,
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Version of February 23, 2013 Abstract Handling errors Declaring, creating and handling exceptions
More informationCOMP200 EXCEPTIONS. OOP using Java, based on slides by Shayan Javed
1 1 COMP200 EXCEPTIONS OOP using Java, based on slides by Shayan Javed Exception Handling 2 3 Errors Syntax Errors Logic Errors Runtime Errors 4 Syntax Errors Arise because language rules weren t followed.
More informationA Third Look At Java. Chapter Seventeen Modern Programming Languages, 2nd ed. 1
A Third Look At Java Chapter Seventeen Modern Programming Languages, 2nd ed. 1 A Little Demo public class Test { public static void main(string[] args) { int i = Integer.parseInt(args[0]); int j = Integer.parseInt(args[1]);
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 informationExceptions in Java
Exceptions in Java 3-10-2005 Opening Discussion Do you have any questions about the quiz? What did we talk about last class? Do you have any code to show? Do you have any questions about the assignment?
More informationChapter 10. Exception Handling. Java Actually: A Comprehensive Primer in Programming
Chapter 10 Exception Handling Lecture slides for: Java Actually: A Comprehensive Primer in Programming Khalid Azim Mughal, Torill Hamre, Rolf W. Rasmussen Cengage Learning, 2008. ISBN: 978-1-844480-933-2
More informationCSCI Object Oriented Design: Java Review Errors George Blankenship. Java Review - Errors George Blankenship 1
CSCI 6234 Object Oriented Design: Java Review Errors George Blankenship Java Review - Errors George Blankenship 1 Errors Exceptions Debugging Java Review Topics Java Review - Errors George Blankenship
More informationCSCI Object-Oriented Design. Java Review Topics. Program Errors. George Blankenship 1. Java Review Errors George Blankenship
CSCI 6234 Object Oriented Design: Java Review Errors George Blankenship George Blankenship 1 Errors Exceptions Debugging Java Review Topics George Blankenship 2 Program Errors Types of errors Compile-time
More informationCOMP1008 Exceptions. Runtime Error
Runtime Error COMP1008 Exceptions Unexpected error that terminates a program. Undesirable Not detectable by compiler. Caused by: Errors in the program logic. Unexpected failure of services E.g., file server
More informationException Handling. Chapter 11. Java By Abstraction Chapter 11. Outline What Are Exceptions?
Chapter 11 Exception Handling Java By Abstraction 11-1 Outline 11.1 What are Exceptions? 11.1.1 Exception Handling 11.1.2 The Delegation Model 11.2 Java's Exception Constructs 11.2.1 The Basic -catch Construct
More informationITI Introduction to Computing II
ITI 1121. Introduction to Computing II Marcel Turcotte School of Electrical Engineering and Computer Science Version of February 23, 2013 Abstract Handling errors Declaring, creating and handling exceptions
More informationIntroduction to Java https://tinyurl.com/y7bvpa9z
Introduction to Java https://tinyurl.com/y7bvpa9z Eric Newhall - Laurence Meyers Team 2849 Alumni Java Object-Oriented Compiled Garbage-Collected WORA - Write Once, Run Anywhere IDE Integrated Development
More informationCMSC131. Exceptions and Exception Handling. When things go "wrong" in a program, what should happen.
CMSC131 Exceptions and Exception Handling When things go "wrong" in a program, what should happen. Go forward as if nothing is wrong? Try to handle what's going wrong? Pretend nothing bad happened? Crash
More information16-Dec-10. Consider the following method:
Boaz Kantor Introduction to Computer Science IDC Herzliya Exception is a class. Java comes with many, we can write our own. The Exception objects, along with some Java-specific structures, allow us to
More informationWhat is the purpose of exceptions and exception handling? Vocabulary: throw/raise and catch/handle Exception propagation Java checked and unchecked
What is the purpose of exceptions and exception handling? Vocabulary: throw/raise and catch/handle Exception propagation Java checked and unchecked exceptions Java try statement Final wishes Java try-resource
More informationExceptions and Design
Exceptions and Exceptions and Table of contents 1 Error Handling Overview Exceptions RuntimeExceptions 2 Exceptions and Overview Exceptions RuntimeExceptions Exceptions Exceptions and Overview Exceptions
More informationHere is a hierarchy of classes to deal with Input and Output streams.
PART 15 15. Files and I/O 15.1 Reading and Writing Files A stream can be defined as a sequence of data. The InputStream is used to read data from a source and the OutputStream is used for writing data
More informationIntroduction to Software Design
CSI 1102 1 Abdulmotaleb El Saddik University of Ottawa School of Information Technology and Engineering (SITE) Multimedia Communications Research Laboratory (MCRLab) Distributed Collaborative Virtual Environments
More informationJAC444 - Lecture 4. Segment 1 - Exception. Jordan Anastasiade Java Programming Language Course
JAC444 - Lecture 4 Segment 1 - Exception 1 Objectives Upon completion of this lecture, you should be able to: Separate Error-Handling Code from Regular Code Use Exceptions to Handle Exceptional Events
More informationError Handling in C++
Error Handling in C++ Exceptions, once thrown, must be caught by specialized error-handling code. If an exception goes uncaught, the program will crash to the desktop. Error Handling Many of C++ s built-in
More informationLecture 07 Debugging Programs with GDB
Lecture 07 Debugging Programs with GDB In this lecture What is debugging Most Common Type of errors Process of debugging Examples Further readings Exercises What is Debugging Debugging is the process of
More informationCS2: Debugging in Java
CS2: Debugging in Java 1. General Advice Jon Cook (LFCS) April 2003 Debugging is not always easy. Some bugs can take a long time to find. Debugging concurrent code can be particularly difficult and time
More informationCOMP-202 Unit 9: Exceptions
COMP-202 Unit 9: Exceptions Course Evaluations Please do these. -Fast to do -Used to improve course for future. (Winter 2011 had 6 assignments reduced to 4 based on feedback!) 2 Avoiding errors So far,
More informationCS 231 Data Structures and Algorithms, Fall 2016
CS 231 Data Structures and Algorithms, Fall 2016 Dr. Bruce A. Maxwell Department of Computer Science Colby College Course Description Focuses on the common structures used to store data and the standard
More informationCS159. Nathan Sprague
CS159 Nathan Sprague What s wrong with the following code? 1 /* ************************************************** 2 * Return the mean, or -1 if the array has length 0. 3 ***************************************************
More informationChapter 12 Exception Handling
Chapter 12 Exception Handling 1 Motivations Goal: Robust code. When a program runs into a runtime error, the program terminates abnormally. How can you handle the runtime error so that the program can
More informationChapter 11 Handling Exceptions and Events. Chapter Objectives
Chapter 11 Handling Exceptions and Events Chapter Objectives Learn what an exception is See how a try/catch block is used to handle exceptions Become aware of the hierarchy of exception classes Learn about
More informationMcGill University School of Computer Science COMP-202A Introduction to Computing 1
McGill University School of Computer Science COMP-202A Introduction to Computing 1 Midterm Exam Thursday, October 26, 2006, 18:00-20:00 (6:00 8:00 PM) Instructors: Mathieu Petitpas, Shah Asaduzzaman, Sherif
More informationException in thread "main" java.lang.arithmeticexception: / by zero at DefaultExceptionHandling.main(DefaultExceptionHandling.
Exceptions 1 Handling exceptions A program will sometimes inadvertently ask the machine to do something which it cannot reasonably do, such as dividing by zero, or attempting to access a non-existent array
More informationExceptions. Author: Boaz Kantor The Interdisciplinary Center, Herzliya Introduction to Computer Science Winter Semester
Exceptions Author: Boaz Kantor The Interdisciplinary Center, Herzliya Introduction to Computer Science Winter 2008-9 Semester 2007-9 Boaz Kantor, Why Exceptions? Give me a number between 1 and 10, and
More informationObject Oriented Programming. Week 7 Part 1 Exceptions
Object Oriented Programming Week 7 Part 1 Exceptions Lecture Overview of Exception How exceptions solve unexpected occurrences Catching exceptions Week 7 2 Exceptions Overview Week 7 3 Unexpected Occurances
More informationChapter 15. Exception Handling. Chapter Goals. Error Handling. Error Handling. Throwing Exceptions. Throwing Exceptions
Chapter 15 Exception Handling Chapter Goals To learn how to throw exceptions To be able to design your own exception classes To understand the difference between checked and unchecked exceptions To learn
More informationExceptions, try - catch - finally, throws keyword. JAVA Standard Edition
Exceptions, try - catch - finally, throws keyword JAVA Standard Edition Java - Exceptions An exception (or exceptional event) is a problem that arises during the execution of a program. When an Exception
More informationCorrectness and Robustness
Correctness and Robustness 188230 Advanced Computer Programming Asst. Prof. Dr. Kanda Runapongsa Saikaew (krunapon@kku.ac.th) Department of Computer Engineering Khon Kaen University 1 Agenda Introduction
More informationCOMP-202 Unit 9: Exceptions
COMP-202 Unit 9: Exceptions Announcements - Assignment 4: due Monday April 16th - Assignment 4: tutorial - Final exam tutorial next week 2 Exceptions An exception is an object that describes an unusual
More informationSome examples and/or figures were borrowed (with permission) from slides prepared by Prof. H. Roumani. Exception Handling
Some examples and/or figures were borrowed (with permission) from slides prepared by Prof. H. Roumani Exception Handling There are three sources that can lead to exceptions: The End User Garbage-in, garbage-out
More informationExceptions Questions https://www.journaldev.com/2167/java-exception-interview-questionsand-answers https://www.baeldung.com/java-exceptions-interview-questions https://javaconceptoftheday.com/java-exception-handling-interviewquestions-and-answers/
More informationIntroduction Unit 4: Input, output and exceptions
Faculty of Computer Science Programming Language 2 Object oriented design using JAVA Dr. Ayman Ezzat Email: ayman@fcih.net Web: www.fcih.net/ayman Introduction Unit 4: Input, output and exceptions 1 1.
More informationObject Oriented Programming
Object Oriented Programming Java lecture (10.2) Exception Handling 1 Outline Throw Throws Finally 2 Throw we have only been catching exceptions that are thrown by the Java run-time system. However, it
More informationCS 3 Introduction to Software Engineering. 3: Exceptions
CS 3 Introduction to Software Engineering 3: Exceptions Questions? 2 Objectives Last Time: Procedural Abstraction This Time: Procedural Abstraction II Focus on Exceptions. Starting Next Time: Data Abstraction
More informationI/O Streams. program. Standard I/O. File I/O: Setting up streams from files. program. File I/O and Exceptions. Dr. Papalaskari 1
File I/O and Exceptions CSC 1051 Data Structures and Algorithms I I/O Streams Programs read information from input streams and write information to output streams Dr. Mary-Angela Papalaskari Department
More informationI/O Streams. program. Standard I/O. File I/O: Setting up streams from files. program. File I/O and Exceptions. Dr. Papalaskari 1
File I/O and Exceptions CSC 1051 Data Structures and Algorithms I I/O Streams Programs read information from input streams and write information to output streams Dr. Mary-Angela Papalaskari Department
More informationTypecasts and Dynamic Dispatch. Dynamic dispatch
Typecasts and Dynamic Dispatch Abstract Data Type (ADT) Abstraction Program Robustness Exceptions D0010E Lecture 8 Template Design Pattern Review: I/O Typecasts change the type of expressions as interpreted
More informationEXCEPTION HANDLING. Summer 2018
EXCEPTION HANDLING Summer 2018 EXCEPTIONS An exception is an object that represents an error or exceptional event that has occurred. These events are usually errors that occur because the run-time environment
More informationPROGRAMMING FUNDAMENTALS
PROGRAMMING FUNDAMENTALS Q1. Name any two Object Oriented Programming languages? Q2. Why is java called a platform independent language? Q3. Elaborate the java Compilation process. Q4. Why do we write
More informationChapter 13 Exception Handling
Chapter 13 Exception Handling 1 Motivations When a program runs into a runtime error, the program terminates abnormally. How can you handle the runtime error so that the program can continue to run or
More informationCOSC 123 Computer Creativity. I/O Streams and Exceptions. Dr. Ramon Lawrence University of British Columbia Okanagan
COSC 123 Computer Creativity I/O Streams and Exceptions Dr. Ramon Lawrence University of British Columbia Okanagan ramon.lawrence@ubc.ca Objectives Explain the purpose of exceptions. Examine the try-catch-finally
More informationCOMP-202. Exceptions. COMP Exceptions, 2011 Jörg Kienzle and others
COMP-202 Exceptions Lecture Outline Exceptions Exception Handling The try-catch statement The try-catch-finally statement Exception propagation Checked Exceptions 2 Exceptions An exception is an object
More informationUnit 5 - Exception Handling & Multithreaded
Exceptions Handling An exception (or exceptional event) is a problem that arises during the execution of a program. When an Exception occurs the normal flow of the program is disrupted and the program/application
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 informationPace University. Fundamental Concepts of CS121 1
Pace University Fundamental Concepts of CS121 1 Dr. Lixin Tao http://csis.pace.edu/~lixin Computer Science Department Pace University October 12, 2005 This document complements my tutorial Introduction
More information9. Java Errors and Exceptions
Errors and Exceptions in Java 9. Java Errors and Exceptions Errors and exceptions interrupt the normal execution of the program abruptly and represent an unplanned event. Exceptions are bad, or not? Errors,
More informationTopic 6: Exceptions. Exceptions are a Java mechanism for dealing with errors & unusual situations
Topic 6: Exceptions Exceptions are a Java mechanism for dealing with errors & unusual situations Goals: learn how to... think about different responses to errors write code that catches exceptions write
More informationChapter 1 Getting Started
Chapter 1 Getting Started The C# class Just like all object oriented programming languages, C# supports the concept of a class. A class is a little like a data structure in that it aggregates different
More informationExceptions vs. Errors Exceptions vs. RuntimeExceptions try...catch...finally throw and throws
Lecture 14 Summary Exceptions vs. Errors Exceptions vs. RuntimeExceptions try...catch...finally throw and throws 1 By the end of this lecture, you will be able to differentiate between errors, exceptions,
More informationNational University. Faculty of Computer Since and Technology Object Oriented Programming
National University Faculty of Computer Since and Technology Object Oriented Programming Lec (8) Exceptions in Java Exceptions in Java What is an exception? An exception is an error condition that changes
More informationSupplemental Handout: Exceptions CS 1070, Spring 2012 Thursday, 23 Feb 2012
Supplemental Handout: Exceptions CS 1070, Spring 2012 Thursday, 23 Feb 2012 1 Objective To understand why exceptions are useful and why Visual Basic has them To gain experience with exceptions and exception
More informationException Examples. All examples written by Edith Hemaspaandra and modified by Jessica Bayliss
Exception Examples All examples written by Edith Hemaspaandra and modified by Jessica Bayliss using System; // An example showing how exceptions propogate. public static int divide( int n, int m ) { return
More information6.Introducing Classes 9. Exceptions
6.Introducing Classes 9. Exceptions Sisoft Technologies Pvt Ltd SRC E7, Shipra Riviera Bazar, Gyan Khand-3, Indirapuram, Ghaziabad Website: www.sisoft.in Email:info@sisoft.in Phone: +91-9999-283-283 Learning
More informationAssertions and Exceptions Lecture 11 Fall 2005
Assertions and Exceptions 6.170 Lecture 11 Fall 2005 10.1. Introduction In this lecture, we ll look at Java s exception mechanism. As always, we ll focus more on design issues than the details of the language,
More informationLecture 22: Java. Overall Structure. Classes & Objects. Every statement must end with ';' Carl Kingsford, , Fall 2015
Carl Kingsford, 0-0, Fall 0 Lecture : Java Overall Structure Classes & Objects Every function in Java must be inside a class, which are similar to Go's struct s. For example: 8 9 0 8 9 class MyProgram
More informationSelected Java Topics
Selected Java Topics Introduction Basic Types, Objects and Pointers Modifiers Abstract Classes and Interfaces Exceptions and Runtime Exceptions Static Variables and Static Methods Type Safe Constants Swings
More informationComputer Science is...
Computer Science is... Automated Software Verification Using mathematical logic, computer scientists try to design tools to automatically detect runtime and logical errors in huge, complex programs. Right:
More information