On Error Vbscript Msdn
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On Error Resume Next Vbscript
Channel 9 Documentation APIs and reference Dev centers Samples Retired content We’re sorry. The on error resume next vba content you requested has been removed. You’ll be auto redirected in 1 second. VBScript VBScript Language Reference Statements (VBScript) Statements (VBScript) On Error Statement error handling in vbscript tutorial On Error Statement On Error Statement Call Statement Class Statement (VBScript) Const Statement (VBScript) Dim Statement Do...Loop Statement Erase Statement Execute Statement ExecuteGlobal Statement Exit Statement For Each...Next Statement For...Next Statement Function Statement (VBScript) If...Then...Else Statement On Error Statement Option Explicit Statement Private Statement Property Get Statement
Vbscript On Error Exit
Property Let Statement Property Set Statement Public Statement Randomize Statement ReDim Statement Rem Statement Select Case Statement Set Statement Stop Statement Sub Statement While...Wend Statement With Statement (VBScript) TOC Collapse the table of content Expand the table of content This documentation is archived and is not being maintained. This documentation is archived and is not being maintained. On Error Statement Enables or disables error-handling.Syntax Copy On Error Resume Next On Error GoTo 0 RemarksIf you don't use an On Error Resume Next statement anywhere in your code, any run-time error that occurs can cause an error message to be displayed and code execution stopped. However, the host running the code determines the exact behavior. The host can sometimes opt to handle such errors differently. In some cases, the script debugger may be invoked at the point of the erro
LippertAugust 19, 200419 Share 0 0 OK, enough about the Peloponnesian war -- a number of readers have asked me questions about error handling in VBScript recently, so I think I'll on error resume next example talk about it a bit for the next few days. Today, I vbscript error handling best practices want to very carefully describe what the error handling semantics are in the language, because there is some
Vbscript Error Handling Line Number
confusion over how exactly it works. There are two statements that affect error handling in VBScript: On Error Resume NextOn Error Goto 0 The meaning of the first seems clear https://msdn.microsoft.com/en-us/library/53f3k80h(v=vs.84).aspx -- if you get an error, ignore it and resume execution on the next statement. But as we'll see, there are some subtleties. But before that, what the heck is up with the second statement? The second statement turns off ‘resume next' mode if it is on. Yes, the syntax is ridiculous -- something like On Error Raise would be a https://blogs.msdn.microsoft.com/ericlippert/2004/08/19/error-handling-in-vbscript-part-one/ whole lot more clear. But for historical purposes, this is what we're stuck with. Visual Basic has an error handling mode which VBScript does not -- VB can branch to a labeled or numbered statement. (Remember line numbers? Those were the days!) To tell VB that you no longer wish to branch to that statement, you give zero, an invalid line number. C'est super-beaucoup-de-fromage, n'est-ce pas? But we're stuck with it now. The subtlety in the "resume next" mode is best illustrated with an example. Const InvalidCall = 5Print "Global code start"Blah1Print "Global code end"Sub Blah1() On Error Resume Next Print "Blah1 Start" Blah2 Print "Blah1 End"End SubSub Blah2() Print "Blah2 Start" Err.Raise InvalidCall Print "Blah2 End"End Sub This prints out Global code startBlah1 StartBlah2 StartBlah1 EndGlobal code end Hold on a minute -- when the error happened, Blah1 had already turned ‘resume next' mode on. The next statement after the error raise is Print "Blah2 End" but that statement never got executed. What's going on? What's going on is that the error mode is on a per-pr
LippertAugust 25, 200421 Share 0 0 Apparently I've sparked a discussion amongst the super-geniuses of LtU on various innovative language constructs for handling errors. Fascinating stuff that I'd love to learn more about! But I'll be less highfalutin: no doubt about https://blogs.msdn.microsoft.com/ericlippert/2004/08/25/error-handling-in-vbscript-part-three/ it, error handling in VBScript is a pain in the rear no matter how you slice it. This series was inspired in party by an email from a reader who was interested in the philosophy of http://stackoverflow.com/questions/2202869/what-does-the-on-error-resume-next-statement-do error handling. Here's an excerpt which contrasts two approaches: (my emphasis) I think I'm old school in saying that error handling should be very tight. Handle errors where you expect to find them. Everything else on error is left to fail. I'd rather have a program end in a messy death than to blithely continue on in an unpredictable fashion. Some of my cohorts would rather do broad error handling (whole subroutines or sections of the script). They seem to assume that only the errors they expect will happen. And even if other errors do happen, it's better to have the script finish as best it can than on error resume to do nothing at all. I've talked about this before (at the bottom of the post.) As a professional developer who writes complex C# and C++ code on a large team building a product that will be shipped to millions of people, I agree with the writer. Error handling should be built into the architecture from day one. And of course we have done so in VSTO2 -- we have developed a set of exception classes with error numbers and localizable error strings, and tried to engineer everything so that only the right errors get propagated up to the user. But I'm working in C# and C++, languages specifically designed for implementing complex software written by large teams. VBScript is not such a language -- it was designed for simple administration and web scripts, where often "muddle on through" is exactly what you want it to do. For example, I have a simple script much like this one that I use for doing quick-and-dirty regular expression searches on my hard disk. You’d better believe that On Error Resume Next is on for that script! If it encounters a directory or file that it cannot search because it is locked by another process, or that I don't have permission to read, or
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 Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack 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 What does the “On Error Resume Next” statement do? up vote 41 down vote favorite 4 I came to some VBScript examples, and I saw the statement On Error Resume Next basically at the beginning of the script. What does it do? vbscript error-handling share|improve this question edited Feb 4 '10 at 20:42 Helen 18.3k44174 asked Feb 4 '10 at 20:18 Omar 3,364114280 4 It is a very powerful, but dangerous bit of syntax. Be very cautious using it. –Nate Feb 4 '10 at 20:22 2 It makes more sense now. After some functions that can end up in error. They have a function called checkError after them. –Omar Feb 4 '10 at 20:37 add a comment| 6 Answers 6 active oldest votes up vote 56 down vote accepted It basically tells the program when you encounter an error just continue at the next line. share|improve this answer answered Feb 4 '10 at 20:19 David 2,2601523 add a comment| up vote 24 down vote It's worth noting that even when On Error Resume Next is in effect, the Err object is still populated when an error occurs, so you can still do C-style error handling. On Error Resume Next DangerousOperationThatCouldCauseErrors If Err Then WScript.StdErr.WriteLine "error " & Err.Number WScript.Quit 1 End If On Error GoTo 0 share|improve this answer answered Feb 5 '10 at 15:49 Tmdean 6,5002645 add a comment| up vote 19 down vote When an error occurs, the execution will continue on the next line without interrupting the script. share|improve this answer answered Feb 4 '10 at 20:19 Pierre-Alain Vigeant 13.7k44388 add a comment| up vote 8 down vote It means, when an error happens on the line, it is telling vbscript to continue execution without aborting the script. Sometimes, the On Error follows the Goto label to alter the flow of execution, something like this in a Sub code block, now you know why and how the usage of GOTO can result in spaghetti code: Sub MySubRoutine() On Error Goto ErrorHandler REM VB code... REM More VB Code... Exit_MySubRoutine: REM Disable the Error Handler! On Error Goto 0 REM Leave.... Exit Sub ErrorHandler: REM Do something about the Error Goto Exit_MySubRoutine End Sub Hope thi