Why is variable remains "null for no reason even after I set the value to equal something

[kdleaver1974]

OK,

I have a STRING Variable that will not accept a value. When I "debug" the program, and I look to see if the variable has the correct value, it shows the value as null. What is going on???

The variable is dimensioned using GLOBAL so the value is retained and used in multiple modules. What am I overlooking?

Here is the relevant code:

ElseIf comboAddInvoice_Vendor.ListIndex = 6 Then
AddInvoiceVendor = "WALTHERS" ' <------------- THIS VARIABLE IS UPDATED
FLAGShippingCost = "N" ' <------------ THIS VARIABLE REMAINS NULL

Thanks all.

Ken L

[June7]

A variable declared as STRING type cannot be Null. It could be empty string.

Variable is declared in a general module?

When do you check the variable content - after the line has executed?

Are you sure about the spelling?

Do you have Option Explicit in every module header?

[kdleaver1974]

A variable declared as STRING type cannot be Null. It could be empty string.

Variable is declared in a general module?

When do you check the variable content - after the line has executed?

Are you sure about the spelling?

Do you have Option Explicit in every module header?

Yes, Global is in a General Module labeled "DIMVARIABLES" and is the first thing that is loaded.
I inserted a breakpoint on the first line after the "End if" statements, see here the entire If-Then block:

' ***********************************


If comboAddInvoice_Vendor.ListIndex = 0 Then

AddInvoiceVendor = "HEARTLAND"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 1 Then

AddInvoiceVendor = "HOBBYTYME"
FLAGShippingCost = "Y"

ElseIf comboAddInvoice_Vendor.ListIndex = 2 Then

AddInvoiceVendor = "INTERMOUNTAIN"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 3 Then

AddInvoiceVendor = "JOANN"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 4 Then

AddInvoiceVendor = "BOBSMITHIND"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 5 Then

AddInvoiceVendor = "SDCPRODUCTIONS"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 6 Then

AddInvoiceVendor = "WALTHERS"
FLAGShippingCost = "N"

ElseIf comboAddInvoice_Vendor.ListIndex = 7 Then

AddInvoiceVendor = "MICHEALS"
FLAGShippingCost = "N"

End If

' ***********************************


If FLAGShippingCost = "N" Then ' <-----THIS IS WHERE I HAVE BREAKPOINT

Spelling is correct, as the variable is "formated" by what it is by the GLOBAL statement. So if I type GLOBAL FLAGShippingCOST as String, the "OST" is capitalized for all these variables.

What does Option Explicit do? I have never heard of this. On the top of this and every other module is "Option Compare Database". Should it be something else. Thanks

Ken L

[June7]

Option Explicit forces variable declaration. It can help locate misspelling when variable is used.

This is an application setting from the VBE Editor > Tools > Options > check Require Variable Declaration

This will cause the line to be included with a new module. Manually add to existing modules if you want it.

If you want to provide db for analysis, follow instructions at bottom of my post.

[kdleaver1974]

Thanks for the offer, but there are several tables and forms making the database very complicated, and I don't have a "clean" program. I have had professional programmers look at my coding and they roll their eyes at me.

I made the change to Option Explicit, and it didn't work.

I did change the name of the variable, and for some reason that works. So could it be the name I am using for this variable? What could be causing this?

Thanks again.

Ken L

FOLLOW UP - I used Debug.print and the variable value prints as being "N" but when I use an IF-THEN statement, so IF FLAGShippingCost = "N" then, it determines it does not equal "N", and during a "pause" I move the cursor over the variable it shows it as empty. This is even more confusing. UGH!

[June7]

I can't see anything in posted code to cause that. I would have to examine db.

So why are you using If Then structure to pull Vendor and FLAG data? Isn't that info in Vendors table? Isn't vendor name a column of combobox? Reference combobox columns by Index.

AddInvoiceVendor = comboAddInvoice_Vendor.Column(1)
FLAGShippingCost = comboAddInvoice_Vendor.Column(2)

Probably won't resolve the issue of FLAGShippingCost showing empty for the Subsequent If test but certainly much shorter code.

Be aware that Global variables lose value when code encounters an unhandled run-time error. This can be a bit annoying when debugging.

[Welshgasman]

Be aware that Global variables lose value when code encounters an unhandled run-time error. This can be a bit annoying when debugging.

That is where Tempvars come in handy.

[Welshgasman]

I inserted a breakpoint on the first line after the "End if" statements, see here the entire If-Then block:

That line has not been executed then? , though that variable should have been set by then.

Any time you are repeating code, there is generally a better way.

If I was writing that, as the variable will be mainly N (only one case of Y?), I would set that at the start of the tests to N, and only code for the Y.

Please show us the DimVariables module.

[moke123]

I made the change to Option Explicit, and it didn't work.

Just to be clear, at the top of every module you should have both

Option Compare Database
Option Explicit

not one or the other.

Then you should compile your code by clicking on debug then Compile database in the vbe.
This will show you if there are any errors in your code.

I think we need to see the whole module not just the if-then portion.

Where are you setting your variables?

You may also want to consider using Public rather than Global.

[June7]

moke, OP said these variables are Global and declared in a general module. They posted the code that is attempting to populate variable with issue.

What advantage does Public have over Global?

[kdleaver1974]

Can't explain why, but when I change the Variable name from "FLAG" to "FLG" it works fine. Can't find a reason why such a change worked, but it did. I came up with the idea after doing various "tests" to see what was happening, and the fact when I used various different variable names, everything worked (I did a Replace all variables in entire Project).

Thanks for the help anyways, and sorry for taking up everyone's time.

Ken L

[kdleaver1974]

moke, OP said these variables are Global and declared in a general module. They posted the code that is attempting to populate variable with issue.

What advantage does Public have over Global?

IIRC, Public doesn't apply to the entire project, only Global seemed to work. At least having the variables in a General Module that is executed at the beginning when the program runs.

Ken L

[moke123]

Global is maintained for backwards compatibility. Public is the recommended keyword due to it's alignment with modern programming practices.

[davegri]

Public doesn't apply to the entire project, only Global seemed to work.

Keep in mind that if a public or global variable is declared in a standard module and assigned a value in some procedure -
If that variable name is Dimmed in any other procedure in your DB, that local variable just dimmed is used in that procedure. The global/public values in the standard module variable are ignored.

So you should search the vba code for those variable names to see if they were re-Dimmed in another procedure.

[June7]

davegri, doesn't quite explain why variable would have correct value in Debug but then following line showed it was empty.

Ken, I tested Public and Global declarations in general module. Both were available for reference in other modules.