473,320 Members | 1,863 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,320 software developers and data experts.

declare DIM within TRY statement

Hi,

I was wondering why when I declare the dim variable outside the try
statement, I could use the .dispose() function but when I declare it inside
the try statement, I get Name 'varname' is not declared.

thanks,
Will
Jul 21 '05 #1
4 2407
Will,
It has to do with variable scope.

If you use:

Dim x As IDisposable
Try
Finally
x.Dispose
End Try

The x variable is at the same scope as the Try itself.

However if you do:

Try
Dim y As IDisposable
Finally
y.Dispose
End Try

The y variable is in the Try's block scope.

Remember that most block statements in VB.NET introduces a new block scope,
allowing each scope to define the same variable.

For details on Scope in VB.NET see:

http://msdn.microsoft.com/library/de...vbconScope.asp

Hope this helps
Jay
"wk6pack" <wk***@sd61.bc.ca> wrote in message
news:uX**************@TK2MSFTNGP09.phx.gbl...
Hi,

I was wondering why when I declare the dim variable outside the try
statement, I could use the .dispose() function but when I declare it
inside
the try statement, I get Name 'varname' is not declared.

thanks,
Will

Jul 21 '05 #2
wk6pack <wk***@sd61.bc.ca> wrote:
I was wondering why when I declare the dim variable outside the try
statement, I could use the .dispose() function but when I declare it inside
the try statement, I get Name 'varname' is not declared.


Where are you trying to use it? In the finally block? If so, that's the
problem - the scope of the try block is just the try block, and with
good reason: the code execution might not have even reached the place
where your variable is declared before an exception is thrown.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #3
thanks for the explanation and reference.

Will
"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:Oi**************@TK2MSFTNGP11.phx.gbl...
Will,
It has to do with variable scope.

If you use:

Dim x As IDisposable
Try
Finally
x.Dispose
End Try

The x variable is at the same scope as the Try itself.

However if you do:

Try
Dim y As IDisposable
Finally
y.Dispose
End Try

The y variable is in the Try's block scope.

Remember that most block statements in VB.NET introduces a new block scope, allowing each scope to define the same variable.

For details on Scope in VB.NET see:

http://msdn.microsoft.com/library/de...vbconScope.asp
Hope this helps
Jay
"wk6pack" <wk***@sd61.bc.ca> wrote in message
news:uX**************@TK2MSFTNGP09.phx.gbl...
Hi,

I was wondering why when I declare the dim variable outside the try
statement, I could use the .dispose() function but when I declare it
inside
the try statement, I get Name 'varname' is not declared.

thanks,
Will


Jul 21 '05 #4
yes, I was trying to use it in the finally block.

Will
"Jon Skeet [C# MVP]" <sk***@pobox.com> wrote in message
news:MP************************@msnews.microsoft.c om...
wk6pack <wk***@sd61.bc.ca> wrote:
I was wondering why when I declare the dim variable outside the try
statement, I could use the .dispose() function but when I declare it inside the try statement, I get Name 'varname' is not declared.


Where are you trying to use it? In the finally block? If so, that's the
problem - the scope of the try block is just the try block, and with
good reason: the code execution might not have even reached the place
where your variable is declared before an exception is thrown.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Jul 21 '05 #5

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

6
by: rick | last post by:
Noob problem. I prefer to keep all my scripts in an external '.js' file. I am currently loading the external '.js' file from the header. Problem is I would like to declare a global variable in the...
7
by: Simon Osborn | last post by:
Hi, Instead of adding my own custom dll's as references into my project, I want to call it via declare statement. However, I'm having a few difficulties! My dll contains a basic function : ...
5
by: Sakharam Phapale | last post by:
Hi All, How to declare the following statement in following structure. szPname As String * MAXPNAMELEN Public Structure MIXERCAPS public wMid As Integer public ...
4
by: wk6pack | last post by:
Hi, I was wondering why when I declare the dim variable outside the try statement, I could use the .dispose() function but when I declare it inside the try statement, I get Name 'varname' is not...
5
by: iwdu15 | last post by:
hi, i need to have a declare statement for an API to call a method in it, the only problem is that i dont neccessarily know where on the comp it will be. I kno it will be in my application folder,...
6
by: John Bailo | last post by:
I created a sproc with 3 input parameters and one output parameter. I want to test it in the "Run SQL Scripts" app of Navigator. I wrote this code: DECLARE RTNDATE CHAR(10) DEFAULT ''; CALL...
2
by: juan.gautier | last post by:
Hi, I try to construct a SQL code for a view to select a specific data from a table, this query take the value of the filter from a text box in a visual basic 6.0 form. my problem is when i...
1
by: okonita | last post by:
Hi all, My environment is DB2 UDBv8.2 on Windows and Linux. I am getting a lot of errors on the script you see below. Some of the error I am geting are: ...
3
by: Lennart | last post by:
Any thoughts on the following scenario anyone? During a performance test I discovered that the application asked one specific query extremely often. It turned out that this particular query...
0
by: DolphinDB | last post by:
The formulas of 101 quantitative trading alphas used by WorldQuant were presented in the paper 101 Formulaic Alphas. However, some formulas are complex, leading to challenges in calculation. Take...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
by: Vimpel783 | last post by:
Hello! Guys, I found this code on the Internet, but I need to modify it a little. It works well, the problem is this: Data is sent from only one cell, in this case B5, but it is necessary that data...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: PapaRatzi | last post by:
Hello, I am teaching myself MS Access forms design and Visual Basic. I've created a table to capture a list of Top 30 singles and forms to capture new entries. The final step is a form (unbound)...
0
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
0
by: Defcon1945 | last post by:
I'm trying to learn Python using Pycharm but import shutil doesn't work
0
by: af34tf | last post by:
Hi Guys, I have a domain whose name is BytesLimited.com, and I want to sell it. Does anyone know about platforms that allow me to list my domain in auction for free. Thank you
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.