On Error Function Vba
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here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us on error vba Learn more about Stack Overflow the company Business Learn more about hiring developers vba error handling best practices or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack try catch vba Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up VBA Excel Error Handling - especially in vba on error exit sub functions - Professional Excel Development Style up vote 5 down vote favorite 4 I got the book "Professional Excel Development" by Rob Bovey and it is opening up my eyes. I am refitting my code with error handling. However, there is a lot I don't understand. I especially need to know how to correctly use it in functions. I use Bovey's rethrow version of the error handler
On Error Goto Line
(at bottom). When I started, I was using the basic boolean (non-rethrow) method and turned my subroutines into boolean functions. (P.S. I am switching back to the boolean method based on the answer.) I need guidance on how to fit functions into this scheme. I want them to return their real values (a string or double, e.g., or -1 if they fail in some cases) so I can nest them in other functions and not just return an error handling boolean. This is what a typical subroutine call to bDrawCellBorders(myWS) would look like within an entry point. Sub calls seem to be working well. (I.e. it is a subroutine that was turned into a function only so it can return a boolean to the error handling scheme.) Sub UpdateMe() ' Entry Point Const sSOURCE As String = "UpdateMe()" On Error GoTo ErrorHandler Set myWS = ActiveCell.Worksheet Set myRange = ActiveCell myWS.Unprotect ' lots of code If Not bDrawCellBorders(myWS) Then ERR.Raise glHANDLED_ERROR ' Call subroutine ' lots of code ErrorExit: On Error Resume Next Application.EnableEvents = True myWS.Protect AllowFormattingColumns:=True Exit Sub ErrorHandler: If bCentralErrorHandler(msMODULE, sSOURCE,,True) Then ' Call as Entry Point Stop Resume Else Resume ErrorExit End If End Sub
three flavors: compiler errors such as undeclared variables that prevent your code from compiling; user data entry error such as a user entering a negative value where only a positive number is acceptable; and run time errors,
Vba On Error Goto 0
that occur when VBA cannot correctly execute a program statement. We will concern ourselves here vba error handling in loop only with run time errors. Typical run time errors include attempting to access a non-existent worksheet or workbook, or attempting to divide err.number vba by zero. The example code in this article will use the division by zero error (Error 11) when we want to deliberately raise an error. Your application should make as many checks as possible during initialization to http://stackoverflow.com/questions/19042604/vba-excel-error-handling-especially-in-functions-professional-excel-developm ensure that run time errors do not occur later. In Excel, this includes ensuring that required workbooks and worksheets are present and that required names are defined. The more checking you do before the real work of your application begins, the more stable your application will be. It is far better to detect potential error situations when your application starts up before data is change than to wait until later to encounter an http://www.cpearson.com/excel/errorhandling.htm error situation. If you have no error handling code and a run time error occurs, VBA will display its standard run time error dialog box. While this may be acceptable, even desirable, in a development environment, it is not acceptable to the end user in a production environment. The goal of well designed error handling code is to anticipate potential errors, and correct them at run time or to terminate code execution in a controlled, graceful method. Your goal should be to prevent unhandled errors from arising. A note on terminology: Throughout this article, the term procedure should be taken to mean a Sub, Function, or Property procedure, and the term exit statement should be taken to mean Exit Sub, Exit Function, or Exit Property. The term end statement should be taken to mean End Sub , End Function, End Property, or just End. The On Error Statement The heart of error handling in VBA is the On Error statement. This statement instructs VBA what to do when an run time error is encountered. The On Error statement takes three forms. On Error Goto 0 On Error Resume Next On Error Goto
United States Australia United Kingdom Japan Newsletters Forums Resource Library Tech Pro Free Trial Membership Membership My Profile People Subscriptions My stuff Preferences Send a message Log Out TechRepublic Search GO Topics: http://www.techrepublic.com/blog/five-apps/five-tips-for-handling-errors-in-vba/ CXO Cloud Big Data Security Innovation Software Data Centers Networking Startups Tech & Work All Topics Sections: Photos Videos All Writers Newsletters Forums Resource Library Tech Pro Free Trial Editions: US United States https://www.tutorialspoint.com/vba/vba_error_handling.htm Australia United Kingdom Japan Membership Membership My Profile People Subscriptions My stuff Preferences Send a message Log Out Software Five tips for handling errors in VBA Effective error handling can mean the difference on error between a seamless, user-friendly experience and a problem-plagued application. These best practices will help ensure your apps run as intended, without a hitch. By Susan Harkins | in Five Apps, October 9, 2010, 1:15 AM PST RSS Comments Facebook Linkedin Twitter More Email Print Reddit Delicious Digg Pinterest Stumbleupon Google Plus A professional application always includes adequate error-handling routines to trap unexpected errors. Sometimes, the right vba error handling handling means the user never knows the error occurred. At the very least, error-handling routines should address the problem, share adequate information on what the user should do next, and exit the program (if absolutely necessary) gracefully. You put a lot of effort into writing the procedures that run your custom applications. Why let a runtime error ruin it all? By employing a few best practices, you can improve error handling. 1: Verify and configure error settings Before you do anything, check the error-trapping settings. VBA, via the Visual Basic Editor (VBE), is flexible and allows you to determine how it responds to errors. To access these settings (shown in Figure A), in the VBE, choose Options from the Tools menu, and click the General tab: Break On All Errors: Stops on every error, even errors following a Resume Next statement. Break On Unhandled Errors: Stops for unhandled errors, but stops on the line calling the class (in class modules) rather than the line with the error, which can be problematic during debugging. Break In Class Modules: Stops at the actual error (line of code), but doesn't work as expected with Err.Raise, which generates an err
- Macro Comments VBA - Message Box VBA - Input Box VBA - Variables VBA - Constants VBA - Operators VBA - Decisions VBA - Loops VBA - Strings VBA - Date and Time VBA - Arrays VBA - Functions VBA - SubProcedure VBA - Events VBA - Error Handling VBA - Excel Objects VBA - Text Files VBA - Programming Charts VBA - Userforms VBA Useful Resources VBA - Quick Guide VBA - Useful Resources VBA - Discussion Selected Reading Developer's Best Practices Questions and Answers Effective Resume Writing HR Interview Questions Computer Glossary Who is Who VBA - Error Handling Advertisements Previous Page Next Page There are three types of errors in programming: (a) Syntax Errors and (b) Runtime Errors (c) Logical Errors. Syntax errors Syntax errors, also called parsing errors, occur at interpretation time for VBScript. For example, the following line causes a syntax error because it is missing a closing parenthesis: Function ErrorHanlding_Demo() dim x,y x = "Tutorialspoint" y = Ucase(x End Function Runtime errors Runtime errors, also called exceptions, occur during execution, after interpretation. For example, the following line causes a runtime error because here syntax is correct but at runtime it is trying to call fnmultiply, which is a non-existing function: Function ErrorHanlding_Demo1() Dim x,y x = 10 y = 20 z = fnadd(x,y) a = fnmultiply(x,y) End Function Function fnadd(x,y) fnadd = x+y End Function Logical errors Logic errors can be the most difficult type of errors to track down. These errors are not the result of a syntax or runtime error. Instead, they occur when you make a mistake in the logic that drives your script and you do not get the result you expected. You can not catch those errors, because it depends on your business requirement what type of logic you want to put in your program. For example, dividi