Exception-Handling Overview

Program logic frequently tests conditions that determine how program execution proceeds. Consider the following pseudocode:

Perform a task
If the preceding task did not execute correctly
     Perform error processing
Perform next task
If the preceding task did not execute correctly
     Perform error processing

In this pseudocode, we begin by performing a task. We then test whether that task executed correctly. If not, we perform error processing. Otherwise, we continue with the next task. Although this form of error handling works, intermixing program logic with error-handling logic can make the program difficult to read, modify, maintain and debugespecially in large applications.

Performance Tip 16.1

If the potential problems occur infrequently, intermixing program logic and error-handling logic can degrade a program's performance, because the program must (potentially frequently) perform tests to determine whether the task executed correctly and the next task can be performed.

Exception handling enables the programmer to remove error-handling code from the "main line" of the program's execution, which improves program clarity and enhances modifiability. Programmers can decide to handle any exceptions they chooseall exceptions, all exceptions of a certain type or all exceptions of a group of related types (e.g., exception types that belong to an inheritance hierarchy). Such flexibility reduces the likelihood that errors will be overlooked and thereby makes a program more robust.

With programming languages that do not support exception handling, programmers often delay writing error-processing code or sometimes forget to include it. This results in less robust software products. C++ enables the programmer to deal with exception handling easily from the inception of a project.

Introduction to Computers, the Internet and World Wide Web

Introduction to C++ Programming

Introduction to Classes and Objects

Control Statements: Part 1

Control Statements: Part 2

Functions and an Introduction to Recursion

Arrays and Vectors

Pointers and Pointer-Based Strings

Classes: A Deeper Look, Part 1

Classes: A Deeper Look, Part 2

Operator Overloading; String and Array Objects

Object-Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism


Stream Input/Output

Exception Handling

File Processing

Class string and String Stream Processing

Web Programming

Searching and Sorting

Data Structures

Bits, Characters, C-Strings and structs

Standard Template Library (STL)

Other Topics

Appendix A. Operator Precedence and Associativity Chart

Appendix B. ASCII Character Set

Appendix C. Fundamental Types

Appendix D. Number Systems

Appendix E. C Legacy Code Topics

Appendix F. Preprocessor

Appendix G. ATM Case Study Code

Appendix H. UML 2: Additional Diagram Types

Appendix I. C++ Internet and Web Resources

Appendix J. Introduction to XHTML

Appendix K. XHTML Special Characters

Appendix L. Using the Visual Studio .NET Debugger

Appendix M. Using the GNU C++ Debugger


C++ How to Program
C++ How to Program (5th Edition)
ISBN: 0131857576
EAN: 2147483647
Year: 2004
Pages: 627

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