Visual Basic 2005 for Programmers: Deitel Developer Series, Second Edition

12.2. Exception Handling Overview

Programs frequently test conditions to determine how program execution should proceed. Consider the following pseudocode:

Perform a taskIf the preceding task did not execute correctly     Perform error process ingPerform next taskIf the preceding task did not execute correctly     Perform error processing...

In this pseudocode, we begin by performing a task; then we 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 programs difficult to read, modify, maintain and debug—especially in large applications.

Exception handling enables you to ...