List occupied cells across multiple cells - vba

Question

I have 4 variables and wish to list which (maximum of 3) variables are being used.
I have used VBA functions before but I am stumped as to the reason this isn't working..
The four variables are percentages so for example:
if (20%,empty,20%,60%) I want the three cells to be (A,C,D)
if (50%,50%,empty,empty) => (A,B,empty)
Hello,
if (empty,empty,100%,empty) => (C,empty,empty)
The code I have at the moment isn't working (for the first cell):
Function whichtoa(w As Integer, x As Integer, y As Integer, z As Integer) As String
If w <> 0 Then
whichtoa = "A"
ElseIf x <> 0 Then
whichtoa = "B"
ElseIf y <> 0 Then
whichtoa = "C"
ElseIf z <> 0 Then
whichtoa = "D"
End If
End Function
Could it be to do with the empty cells being general and the others being a percentage? I can't really change this as the data is coming from another program.
Could I use a null check or something similar?
Thanks in advance!
Lucas

Answer 1

Consider the following data. the last column has the formula for whichtoA
A B C D E
60% 40% 30% 30% ABC
30% 60% 30% 90% ABC
10% 20% 50% ABC
30% 50% BC
30% C
50% 60% CD
If you are using percentages you need to use something other than integer in your function since you're dealing with decimals.
Function whichtoa(w As Double, x As Double, y As Double, z As Double) As String
Dim emptyCount As Integer
Dim results As String
' Assume zero
valueCount = 0
' Assume empty string
results = ""
If w <> 0 Then
results = results & "A"
valueCount = valueCount + 1
End If
If x <> 0 Then
results = results & "B"
valueCount = valueCount + 1
End If
If y <> 0 Then
results = results & "C"
valueCount = valueCount + 1
End If
' This is the only time you need to check the condition of valueCount. If you want 3 maximum
If (z <> 0) And (valueCount < 3) Then
results = results & "D"
End If
whichtoa = results
End Function
Each condition is checked individually. The If block you have will only process the first match and then stop evaluating the block. Then, counting the number of positive values, or hits if you will, with valueCount we can stop processing if we get 3 hits. This only needs to be checked with z parameter in the event we have 3 hits already at that point. Build the results as a string and return it.

Answer 2

Your conditional statement is chained: each ElseIf is only evaluated if the preceding If evaluates to True, so the function will only return a single string value (either A, B, C, or D but not a combination of multiple possible values, which would require stroing them all in a collection/dictionary/array/etc., and removing the ones that are empty values.
Compounded by implied type conversion (presumably you're passing range objects to this function, on a worksheet, which evaluate to their .Value which is "0" if the range is empty.
Another problem you may not have hit yet (if you're still working through the above) is that if the cell values contain percentages, by casting them as Integer in the function declaration, any values which round down to 0 will be evaluated as zero.
I suggest declaring the variables as Range objects, and then specifically check their .Value property. Store ALL cells and a key value ("A", "B", etc.) in a dictionary. Iterate the dictioanry and check the value for emptiness:
I also use this to return an error value if the dictionary contains 4 items, since you want a maximum of 3.
Function whichtoa(a As Range, b As Range, c As Range, d As Range)
Dim dict As Object
Dim itm As Variant
Set dict = CreateObject("Scripting.Dictionary")
'Add each cell value to a dictionary, using unique letter as Key
dict("A") = a.Value
dict("B") = b.Value
dict("C") = c.Value
dict("D") = d.Value
'iterate the dictionary keys, removing empty values
For Each itm In dict.Keys()
If IsEmpty(dict(itm)) Then dict.Remove (itm)
Next
If Not dict.Count = 4 Then
whichtoa = Join(dict.Keys(), ",")
Else:
whichtoa = CVerr(2023)
End If
End Function

Answer 3

I'm not sure exactly what the return value is that you want (your example are inconsistent), but the following may point you in the right direction:
Public Function whichtoa(r as Range)
Dim arr, i
arr = Array("A", "B", "C", "D")
For i = 0 to 3
If IsEmpty(r.Cells(1,i+1) Then
arr(i) = "empty"
End If
Next
whichtoa = arr(0) & "," & arr(1) & "," & arr(2) & "," & arr(3)
End Function