In Excel VBA, how to convert SUM function to its explicit form? - excel

Question

The excel cell has a formula of form =SUM(I1:I5). How can we convert it into its explicit form:
=I1+I2+I3+I4+I5

Answer 1

Another approach with .Precedents:
Sub expandSUM()
Range("A1").Formula = "=SUM(I1:I5)" 'the formula must be in the cell
Output = "=SUM("
For Each cl In Range("A1").Precedents
Output = Output & "+" & cl.Address(False, False)
Next
Debug.Print Replace(Output, "(+", "(") & ")"
End Sub

Answer 2

This feels like a post on Code Golf. Here's my version of a function that can do this.
Function ExplicitSum(ByVal expression As String) As String
Dim strStart As Long, strEnd As Long
strStart = InStr(1, UCase(expression), "SUM(") + 4
If strStart = 0 Then
'SUM not found
ExplicitSum = expression
Exit Function
End If
strEnd = InStr(strStart + 1, expression, ")")
If strEnd = 0 Then
'closing bracket not found
ExplicitSum = expression
Exit Function
End If
Dim LeftText As String, RightText As String, AddressText As String
LeftText = Replace(Left(expression, strStart - 1), "sum(", "(", Compare:=vbTextCompare)
AddressText = Mid(expression, strStart, strEnd - strStart)
RightText = Right(expression, Len(expression) - strEnd + 1)
If InStr(1, UCase(RightText), "SUM(") <> 0 Then
'Recursion will handle multiple sums in the same formula
RightText = ExplicitSum(RightText)
End If
Dim SumRange As Range
On Error Resume Next
Set SumRange = Range(AddressText)
On Error GoTo 0
If SumRange Is Nothing Then
'Invalid AddressText - Named Ranges or Indirect reference
ExplicitSum = LeftText & AddressText & RightText
Exit Function
End If
Dim Addresses() As String
ReDim Addresses(1 To SumRange.Cells.Count)
Dim cell As Range, i As Long: i = 1
For Each cell In SumRange
Addresses(i) = cell.Address(False, False)
i = i + 1
Next cell
ExplicitSum = LeftText & Join(Addresses, "+") & RightText
End Function
Examples of how to use the function:
Sub test()
MsgBox ExplicitSum("=5+sum(A1:D1)/20")
'Displays "=5+(A1+B1+C1+D1)/20"
End Sub
Sub ExampleUsage()
'Put the formula back into the cell after transforming
Range("E1").Formula = ExplicitSum(Range("E1").Formula)
End Sub
Private Sub Worksheet_Change(ByVal Target As Range)
'Run on every cell with SUM in its formula
If LCase(Target.Cells(1,1).Formula) Like "*sum(*" Then Target.Cells(1,1).Formula = ExplicitSum(Target.Cells(1,1).Formula)
End Sub
Will work with complex formulas.
Will work with multiple SUMS in the same formula.
Will work with Named Ranges inside the Sum.

Answer 3

I wrote a function to do this via string manipulations.
I tested with
Before =SUM(C2:C4,E2:G2,D7:E8)
After =$C$2+$C$3+$C$4+$E$2+$F$2+$G$2+$D$7+$E$7+$D$8+$E$8
Usage, call ExpandSum() with the target cell as an argument
Public Sub ExpandSum(ByVal r_target As Range)
Dim f As String
f = Mid(r_target.Formula, 2)
' Is it a SUM function
If Left(f, 3) = "SUM" Then
' Take the arguments of SUM
f = Mid(f, 5, Len(f) - 5)
' make an array of string with each
' arument
Dim parts() As String
parts = Split(f, ",")
Dim i As Long, n As Long
n = UBound(parts) + 1
Dim rng As Range, cl As Range
Dim col As New Collection
For i = 1 To n
' for each argument find the range of cells
Set rng = Range(parts(i - 1))
For Each cl In rng
' Add each cell in range into a list
col.Add cl.Address
Next
Next i
' Transfer list to array
ReDim parts(0 To col.Count - 1)
For i = 1 To col.Count
parts(i - 1) = col(i)
Next i
' Combine parts into one expression
' ["A1","A2","A3"] => "A1+A2+A3"
f = Join(parts, "+")
r_target.Formula = "=" & f
End If
End Sub
Example of calling with the current selection
Public Sub ThisExpandSum()
Call ExpandSum(Selection)
End Sub
Caveats I don't know how it will behave if the sum contains literal values, or cells from different sheets. That can be functionality to be added later.

Answer 4

Use the next function, please:
Function SUMbyItems(strFormula As String) As String
If strFormula = "" Then Exit Function
Dim rng As Range, Ar As Range, c As Range, strF As String
Set rng = Range(left(Split(strFormula, "(")(1), Len(Split(strFormula, "(")(1)) - 1))
For Each Ar In rng.Areas
For Each c In Ar.cells
strF = strF & c.Address(0, 0) & "+"
Next c
Next
strF = left(strF, Len(strF) - 1)
SUMbyItems = "=SUM(" & strF & ")"
End Function
It can be used, selecting a cell having a SUM formula containing a range and run the next Sub:
Sub testSumByItems()
Debug.Print SUMbyItems(ActiveCell.Formula)
End Sub
If it returns what you want and you need changing the range formula with its expanded version, you can use (in the above testing Sub):
ActiveCell.Formula = SUMbyItems(ActiveCell.Formula)