How to display calculations, values and variables in Excel? - vba

Question

For didactic purposes I like to perform and display calculations in Excel. To display calculations I use the following VBA worksheet-function:
Function DisplayFormula(range_rng As Range) As String
Application.Volatile
If range_rng.HasArray Then
DisplayFormula = "<-- " & " {" & range_rng.FormulaArray & "}"
Else
DisplayFormula = "<-- " & " " & range_rng.FormulaArray
End If
End Function
This works, however, I'm stuck with the implementation of two modifications:
I would like to display the actual values that are called in range_rng.
I would like to display variables instead of the ranges. The variables would be assigned in a separate cell, next to the cell where they are called from (see graphic below).
Column "C" shows the (desired) output formats for DisplayFormula(B3):

Answer 1

You can try this brute force approach.
I can't say that this is optimized, but it can satisfy your two conditions above.
Function DisplayFormula2(r As Range, Optional o As Variant) As String
Dim a, b, z, x, y, w
Dim f As String, tf As String
Dim c As Range
Dim i As Integer
If IsMissing(o) Then o = 0
a = Array("+", "-", "/", "*", "%", "&", "^", "=", _
"<", ">", "<=", ">=", "<>", "(", ")")
f = r.FormulaArray: tf = f
For Each b In a
With Application.WorksheetFunction
tf = .Substitute(tf, b, "|")
End With
Next
z = VBA.Split(tf, "|")
For Each w In z
Debug.Print w
On Error Resume Next
Set c = Range(w)
On Error GoTo 0
If Not c Is Nothing Then
If IsArray(x) Then
ReDim Preserve x(UBound(x) + 1): x(UBound(x)) = w
ReDim Preserve y(UBound(y) + 1): y(UBound(y)) = c.Offset(0, o).Value2
Else
x = Array(w)
y = Array(c.Offset(0, o).Value2)
End If
End If
Set c = Nothing
Next
If IsArray(x) Then
For i = LBound(x) To UBound(x)
With Application.WorksheetFunction
f = .Substitute(f, x(i), y(i))
End With
Next
End If
DisplayFormula2 = IIf(r.HasArray, "<-- {" & f & "}", "<-- " & f)
End Function
By the way, I don't think you need to use .Volatile so I removed it.
It will recalculate as long as you set Calculation mode to Automatic.
Actual Formula in C3:C5:
C3: =DisplayFormula(B3)
C4: =DisplayFormula2(B4)
C5: =DisplayFormula2(B5,-1)

Answer 2

You can achieve that by changing the target cell to TEXT format. Try this:
Function DisplayFormula(range_rng As Range) As String
Application.Volatile
ActiveCell.NumberFormat = "#"
If range_rng.HasArray Then
DisplayFormula = "<-- " & " {" & range_rng.FormulaArray & "}"
Else
DisplayFormula = "<-- " & " " & range_rng.FormulaArray
End If
End Function