Tricky data type error
 

Was caught out by something tricky that I thought might be worth it to pass
on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there obviously will be
an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far as I can see
never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably at compile
time?


RBS

Tricky data type error
 

Strangely (at least to me) this runs:

Sub test()

Dim strTest As String

strTest = 2

If strTest = 4 Then
MsgBox strTest
End If

End Sub

But this doesn't:


Sub test()

Dim strTest As String

strTest = "a"

If strTest = 4 Then
MsgBox strTest
End If

End Sub


This might in fact explain the different behaviour on the different
machines, rather than the Excel version.


RBS


"RB Smissaert" wrote in message
...
Was caught out by something tricky that I thought might be worth it to
pass on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there obviously will be
an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far as I can see
never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably at compile
time?


RBS

Tricky data type error
 

I've never seen a situation in which that code wouldn't compile.
Of course, it blows up at run-time, but it should compile.

No, there's no way to catch such errors when you write or compile
the code.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"RB Smissaert" wrote in message
...
Was caught out by something tricky that I thought might be
worth it to pass on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there
obviously will be an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far
as I can see never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably at
compile time?


RBS

Tricky data type error
 

Well, I definitely have seen a compile error with this.
Thanks for confirming it can't be caught normally at compile time.

RBS

"Chip Pearson" wrote in message
...
I've never seen a situation in which that code wouldn't compile. Of
course, it blows up at run-time, but it should compile.

No, there's no way to catch such errors when you write or compile the
code.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"RB Smissaert" wrote in message
...
Was caught out by something tricky that I thought might be worth it to
pass on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there obviously will
be an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far as I can
see never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably at compile
time?


RBS

Tricky data type error
 

Do you remember what the Compiler Error was?


"RB Smissaert" wrote in message
...
Well, I definitely have seen a compile error with this.
Thanks for confirming it can't be caught normally at compile
time.

RBS

"Chip Pearson" wrote in message
...
I've never seen a situation in which that code wouldn't
compile. Of course, it blows up at run-time, but it should
compile.

No, there's no way to catch such errors when you write or
compile the code.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"RB Smissaert" wrote in
message ...
Was caught out by something tricky that I thought might be
worth it to pass on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there
obviously will be an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far
as I can see never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably
at compile time?


RBS

Tricky data type error
 

My mistake not to write it down, but I think it was similar
to the runtime error message.

RBS

"Chip Pearson" wrote in message
...
Do you remember what the Compiler Error was?


"RB Smissaert" wrote in message
...
Well, I definitely have seen a compile error with this.
Thanks for confirming it can't be caught normally at compile time.

RBS

"Chip Pearson" wrote in message
...
I've never seen a situation in which that code wouldn't compile. Of
course, it blows up at run-time, but it should compile.

No, there's no way to catch such errors when you write or compile the
code.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"RB Smissaert" wrote in message
...
Was caught out by something tricky that I thought might be worth it to
pass on.

Had coded, simplified, this code:

Sub test()

Dim strTest As String

If strTest = 4 Then
MsgBox strTest
End If

End Sub

Strangely, this sometimes compiles and sometimes doesn't.
Unfortunately, it did with me, but it can't run as there obviously will
be an error:
Type mismatch (Error 13)
Strangely also it can sometimes run on Excel 2003, but as far as I can
see never on 2000.
Just completely unpredictable.

Would there be a way to catch out this coding error reliably at compile
time?


RBS

Tricky data type error
 

I think it has to do with certain assumption excel makes during runtime

If you try to place a non Compatable value in a variable. It will tr
to convert that variable into the type required and place the value i
it. However depending on what goes on with the variable beforehand i
may or May not be able to do this. When you declare a variable

Dim strtest as Strin

You DIMension up an area of memory in a "format" to receive strin
type. BUT strtest ISNT yet a string. This is decided when it gets i
first value IE strtest = 2 or StrTest = "a" Depending on what you d
from then on determines whether you get an error. It has something t
do with the fact that a String data type is really just a singl
dimension array of characters

While excel will try to work around your errors there are times when i
will just throw up its hands and go "Sod you Im Not Dealing with thi
Rubbish! YOu FIX it!!" IE you get a runtime erro

From memory.....It been awhil

--
Willo
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