How to sum variables in VBA to check input data is correct? - vba

Question

May seem like a stupid question, but how do you sum variables in VBA to check input data is correct?
I'm trying to check the user has inputted data correctly into a UserForm before they continue to the next page. To do this I want to sum some of their input variables. If they don't input it correctly, they get a message box telling them to revise the numbers. My code is:
Dim BinQnt As Double
Dim FillQnt As Double
Dim FineQnt As Double
Dim CoarQnt As Double
Dim RAPQnt As Double
Dim CRQnt As Double
If BinQnt + FillQnt + FineQnt + CoarQnt + RAPQnt + CRQnt = 100 Then
'Code here for inserting values into database. Omitted to save space and confusion.
Else
MsgBox "Error, please check mixture design sums to 100%."
End If
When I'm testing it, it always goes to the error message box and I'm not sure why. Very sure I am adding variables which sum to 100 (haha). I first tried it without defining the variables, and now I have it still doesn't work.
Am I missing something obvious?

Answer 1

Do you want to round it or not?
In your question, you have the variables as Doubles, and in the answer as integers. Having them as integers will make it easier to hit 100%, but it will round to the nearest integer (2,4 = 2 | 2,6 = 3)
I will assume you are using all texboxes in the form, and as such use this code that is universal:
Dim tot As Double
tot = 0
For Each c In Me.Controls
If TypeName(c) = "TextBox" And IsNumeric(c.Value) Then
tot = tot + c.Value
End If
Next c
If tot = 100 Then
'Code here for inserting values into database. Omitted to save space and confusion.
Else
MsgBox "Error, please check mixture design sums to 100%. Currently at " & tot & "%."
End If
This would give us something like this:
However, using Integer or Long, gives us this:
Also, the reason as to why I'm using IsNumeric(c.Value), is to stop the code from failing in case of empty boxes (or filled with invalid entries).
You could also place a check here in case no boxes are allowed to be empty.