How do you separate text in excel vba by "CamelCase" and numbers - excel

Question

I'm trying to make a molecular composition calculator but i can seem to separate a formula by case and numbers into different cells.
Is it possible to do this in excel?
Eg:
Cl2H0 ----> Cl | 2 | H | 0

Answer 1

A bit crude but you could write a parsing function like this that returns an array:
Public Function parseChem(str As String) As Variant()
'should error-check first that entire string is correct
Dim retArr() As Variant
Dim i As Long, numBlocks As Long
Dim currentChar As String, currentElement As String, typeOfChar As String
Dim digitChain As Boolean
For i = 1 To Len(str)
currentChar = Mid(str, i, 1)
typeOfChar = charType(currentChar)
Select Case typeOfChar
Case Is = "upperCase"
If currentElement <> "" Then
'possibly cast numbers to longs here, and at the end...
retArr(numBlocks) = currentElement
End If
numBlocks = numBlocks + 1
ReDim Preserve retArr(1 To numBlocks)
currentElement = currentChar
digitChain = False
Case Is = "lowerCase"
currentElement = currentElement & currentChar
Case Is = "digit"
If digitChain Then
currentElement = currentElement & currentChar
Else
'new digit block
retArr(numBlocks) = currentElement
numBlocks = numBlocks + 1
ReDim Preserve retArr(1 To numBlocks)
digitChain = True
currentElement = currentChar
End If
Case Else
'do something to flag error
End Select
Next i
retArr(numBlocks) = currentElement
parseChem = retArr
End Function
Private Function charType(str As String) As String
Dim ascii As Long
ascii = Asc(str)
If ascii >= 65 And ascii <= 90 Then
charType = "upperCase"
Exit Function
Else
If ascii >= 97 And ascii <= 122 Then
charType = "lowerCase"
Exit Function
Else
If ascii >= 48 And ascii <= 57 Then
charType = "digit"
Exit Function
End If
End If
End If
End Function

Answer 2

OK the algorithm in the end is very simple
If at any point in the formula you have a number, then look for the next capital letter and output all characters up to that point.
If at any point in the formula you have a letter, then look for the next capital letter *or number* and output all characters up to that point.
The formula is rather long
=IF(ISNUMBER(MID($A$1,SUM(LEN($B$1:B1))+1,1)+0),
MID(MID($A$1,SUM(LEN($B$1:B1))+1,9),1,MIN(FIND( MID("ABCDEFGHIJKLMNOPQRSTUVWXYZ",ROW($1:$26),1),MID($A$1,SUM(LEN($B$1:B1))+2,9)&"ABCDEFGHIJKLMNOPQRSTUVWXYZ" ))),
MID(MID($A$1,SUM(LEN($B$1:B1))+1,9),1,MIN(FIND( MID("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",ROW($1:$36),1),MID($A$1,SUM(LEN($B$1:B1))+2,9)&"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" ))))
must be entered as an array formula using CtrlShiftEnter and the 9 would need increasing ( or changing to len($a1) ) if the formula was longer than 9 characters.
Here's a shorter version that doesn't have to be entered as an array formula
=IF(ISNUMBER(MID($A1,SUMPRODUCT(LEN($B1:B1))+1,1)+0),
MID(MID($A1,SUMPRODUCT(LEN($B1:B1))+1,9),1,AGGREGATE(15,6,FIND( MID("ABCDEFGHIJKLMNOPQRSTUVWXYZ",ROW($1:$26),1),MID($A1,SUMPRODUCT(LEN($B1:B1))+2,9)&"A" ),1)),
MID(MID($A1,SUMPRODUCT(LEN($B1:B1))+1,9),1,AGGREGATE(15,6,FIND( MID("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",ROW($1:$36),1),MID($A1,SUMPRODUCT(LEN($B1:B1))+2,9)&"A"),1)))

Answer 3

If you are familiar with VBA then you could write a function which reads in the cell value (e.g. Cl2H0) and then a For Loop that splits the string into seperate values. You would then write these seperated values (Cl, 2, H and 0) back to indivisual columns on the excel sheet.
One way of doing this would be to use the Asc() function in a loop which will give you the Ascii number corresponding to an indivisual charachter. Ascii charachters 65 to 90 are Upper Case charachters. In your case you would want to split the string when the charachter does not fall within this range.
If you want to try this and post your example then I can give some more guidance but its hard to give more advide without first understanding if you are trying to achieve this with VBA or some other means.