Asp Vbscript On Error Goto 0
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the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a vbscript on error goto errorhandler minute: Sign up What does the “on error goto 0” and “error resume next” in old ASP mean? up vote 5 down vote favorite I am working with old ASP code and I am not sure about semantics of on error vbscript on error goto function goto 0 and error resume next construction. Can you recommend me some useful resources or enlight me directly? asp-classic vbscript share|improve this question edited Dec 1 '11 at 20:02 Joel Coehoorn 248k92440661 asked May 13 '09 at 8:12 Jakub Šturc 17.8k196996 add a comment| 5 Answers 5 active oldest votes up vote 4 down vote accepted On error resume next: If there is an exception in the program, just ignore it and continue to the next statement. Considered very bad and ugly,
Vbscript On Error Goto Line
and rightly so in my opinion. It's like having a big: try { // your code } catch { // nothing! muhaha } in every method of your code (or worse, around the whole program). On error goto 0: disables any error handler that is defined in the current procedure. It's like having a big try-catch around your code, which gets disabled as soon as its hit this line. For more information, see the MSDN. share|improve this answer edited May 13 '09 at 8:32 answered May 13 '09 at 8:20 Razzie 19.6k104861 2 +1 Yes. I just discovered this: If you use On Error Goto 0 then every other On Error statement in the procedure becomes disabled. That was totally unexpected. I thought that the documentation was saying that only the last executed error handler is disabled. I expected that if the code reaches another error handler that it would be enabled again but it isn't. –authentictech May 9 '14 at 14:54 add a comment| up vote 4 down vote Have a look here: http://www.powerasp.com/content/new/on-error-resume-next.asp share|improve this answer answered May 13 '09 at 8:20 Seb 411 add a comment| up vote 3 down vote on error go to takes the execution code to a specific code book mark defined in the page.this is useful when you want to perform anything in case an error is encountered. On error resume next moves on to the next code of execution after the erroneous code. Basically
a tutorial example on how to use 'On Error GoTo 0' to turn off the error handling flag in a procedure to catch the first runtime error. As you can see from the previous section, my last VBScript example reported vbscript on error goto sub the last runtime error, not the first one. If you want to catch the first vbscript clear error runtime error is a large section of code, you need to: Enter the "On Error Resume Next" statement in the main code to
Vbs On Error Goto 0
turn on the error handling flag for the main code. Put that section of code into a new subroutine procedure. Enter the "On Error Goto 0" statement in the new procedure to turn off the error handling flag for http://stackoverflow.com/questions/856710/what-does-the-on-error-goto-0-and-error-resume-next-in-old-asp-mean that procedure. Check the Err.Number property right after calling that procedure. Here is the modified VBScript example to catch the first runtime error in a section of code:
Run this modified example code in IE, you will get: There is no error at this time. Before statement: x = 1/0 A runtime error has occurred: Err.Number = 11 Err.Description = Division by zero Err.Source = Microsoft VBScript runtime error What heppened was: When the first runtime error occurred on statement, x = 1/0, in the CodeToBeMonitored() procedure, execution stopped for that procedure, because the error handling flag was turned off for that procedure. Execution control was transferred back to the main code with the runtime error. Back in the main code, the execution continued because the error handling flag was turned on for the main code. When CheckError() was called at the end, Err.Number is 11, indicating that the runtime error occurred was a "Division by zero" error. Now this example code behav
Forums Links DISCUSSIONARCHIVES DISCUSSIONARCHIVES2 DISCUSSIONARCHIVES3 BLOG We didn't realize the site was so popular. Other Stuff How To Use On Error Resume Next Often http://www.powerasp.net/content/new/on-error-resume-next.asp when using ASP or Active Server Pages with VBScript you will find it necessary https://www.prestwoodboards.com/ASPSuite/KB/Document_View.asp?QID=100411 to check for errors when you do certain things that may fail and then handle it accordingly. Things like opening a database connection or writing to a text file come to mind. Generally if an error is encountered in your .asp file, the processing of your script stops and an error message is returned to the on error browser. If you want to continue processing your page even if an error is encountered, include the following line at the beginning of your .asp file: <% On Error Resume Next %> That being said just ignoring errors in your code is not a very good idea. What you really want to do is handle the error in some way. The example below opens a database connection and shows you how on error goto to trap a potential error and do whatever you want because of it. In this case we are simply displaying the error. <% ConnectionString = "DBQ=c:\inetpub\wwwroot\mysite\data\mydatabase.mdb;Driver={Microsoft Access Driver (*.mdb)};" '*** This code checks the ConnectionString info you entered and reports back the error code if it is not ok Err.Clear On Error Resume Next Set ConnPasswords = Server.CreateObject("ADODB.Connection") ConnPasswords.Open ConnectionString If Err.Number <> 0 Then Response.Write (Err.Description& "
") Response.Write("This means there is most likely a problem with the" & vbCrLf) Response.Write("""ConnectionString"" info that you specified.
" & vbCrLf) Response.End End If On Error GoTo 0 %> We put the "On Error GoTo 0 at the end because that will essentially end the "on error resume next" That is something you want to do so any later errors in your application do not get ignored without you knowing about it. Below is another example. In this example our application logs user info in a text file when they sign in to a site. We add "On Error Resume Next" here simply so no nasty error message come up if by chance write permissions to the text file do not exist. <% Set ObjMyFile = CreateObject("Scripting.FileSystemObject") Err.Clear On Error Resume Next LogFileName = "aspprotect.l
Activity -Unanswered Threads -Most Active Threads -Most Read Threads ASP Classic KB -New & Updated -Most Read -10 Min Quickstarts -Recent Comments Tech Articles ASP Classic News Errors Library File Library Resource Links ASP CLASSICTIDBITS: All as FlashCards Code Snippets FAQs Tips ASP Classic To/From To/FromCODEGuides ASP Classic To/From ASP Classic Study Test PRESTWOODCERTIFIED ASP Classic Study Test ASP Classic Store PRESTWOODSTORE Store Home Buy ASP Classic Items Members Only MEMBERSONLY ASP Classic Member List Member Only KB Posts ASP Classic Content Stats Random Article Random MB Thread Random Tidbit Random CrossRef Code Prestwood eMagazine October Edition Subscribe now! It's Free! Enter your email: ► KB ► Website Scri... ► ASP Classic ► Language Basics Print This From the January2009 Issue of Prestwood eMag ASP Classic Language Basics:Using On Error Resume NextBy Mike Prestwood Posted 10 years ago on 11/15/2006 and updated 7/2/2008 Take Away: You can use "On Error Resume Next" to suppress errors and "On Error Goto 0" to stop suppressing errors. Tags: ASP , On Error Resume Next , trap errors , CDO , send email KB100411 ASP's ability to trap for errors is pretty weak compared to other languages. However, you can trap for errors, suppress errors, and stop suppressing errors. When an error is found, you can also handle it. Suppressing Errors To start trapping errors, add the following line:On Error Resume Next This will suppress all errors for the duration of the script. For example, normally the following code would cause the death of your code with a division by error message:Dim xx = 1/0 However, you can suppress the error as follows:On Error Resume NextDim xx = 1/0 The above code will cause NO error at all. Capture Error But Keep Going While trapping for errors, you can handle the error by inspecting the Err object. The following code snippet handles our division by zero error by displaying a message but the script keeps going:On Error Resume NextDim xx = 1/0If Err.Number <> 0 ThenResponse.Write "Error: " & Err.DescriptionEnd IfResponse.Write "Note, this line here still executes and prints this text." Stop Suppressing Errors After calling On Error Resume Next, you can stop suppressing errors with the following