Return a list of column headers across a row when cells have text - vba

Question

I want to get a list of column headers for each cell that contains a text value.
Eg.
A--------------B-------------C-------------BC (desired output)
1 Header1 Header2 Header3
2 M T Header1, Header3
3 T MT Header1, Header2
4 TMW Header2
In the final product I want to use two final columns with formulas listing headers from cells with values across 9 columns and a second with the other 40 odd columns.
I have the vague notion that I might need to use INDEX, MATCH and IF functions - but as a novice have no idea how to string them together coherently.

Answer 1

Here I will make use of VBA's Join function. VBA functions aren't directly available in Excel, so I wrap Join in a user-defined function that exposes the same functionality:
Function JoinXL(arr As Variant, Optional delimiter As String = " ")
JoinXL = Join(arr, delimiter)
End Function
The formula in D2 is:
=JoinXL(IF(NOT(ISBLANK(A2:C2)),$A$1:$C$1&", ",""),"")
entered as an array formula (using Ctrl-Shift-Enter). It is then copied down.
Explanation:
NOT(ISBLANK(A2:C2)) detects which cells have text in them; returns this array for row 2: {TRUE,FALSE,TRUE}
IF(NOT(ISBLANK(A2:C2)),$A$1:$C$1&", ","") converts those boolean values to row 1 contents followed by a comma delimiter; returns the array {"Header A, ","","Header C, "}.
JoinXL joins the contents of that array into a single string.

Answer 2

If you want to use worksheet functions, and not VBA, I suggest returning each column header in a separate cell. You can do this by entering a formula such as:
This formula must be array-entered:
BC: =IFERROR(INDEX($A$1:$C$1,1,SMALL((LEN($A2:$C2)>0)*COLUMN($A2:$C2),COUNTBLANK($A2:$C2)+COLUMNS($A:A))),"")
Adjust the range references A:C to reflect the columns actually used for your data. Be sure to use the same mixed address format as in above. Do NOT change the $A:A reference, however.
Then fill right until you get blanks; and fill down as far as required.
You can reverse the logic to get a list of the "other" headers.
To array-enter a formula, after entering
the formula into the cell or formula bar, hold down
ctrl-shift while hitting enter. If you did this
correctly, Excel will place braces {...} around the formula.
If you really need to have the results as comma-separated values in two different columns, I would suggest the following User Defined Function.
To enter this User Defined Function (UDF), alt-F11 opens the Visual Basic Editor.
Ensure your project is highlighted in the Project Explorer window.
Then, from the top menu, select Insert/Module and
paste the code below into the window that opens.
To use this User Defined Function (UDF), enter a formula like
=Headers($A2:$BA2,$A$1:$BA$1,True)
or, to get the headers that do NOT contain text:
=Headers($A2:$BA2,$A$1:$BA$1,FALSE)
in some cell.
=====================================================
Option Explicit
Function Headers(rData As Range, rHeaders As Range, Optional bTextPresent As Boolean = True) As String
Dim colHeaders As Collection
Dim vData, vHeaders
Const sDelimiter As String = ", "
Dim sRes() As String
Dim I As Long
vData = rData
vHeaders = rHeaders
Set colHeaders = New Collection
For I = 1 To UBound(vData, 2)
If (Len(vData(1, I)) > 0) = bTextPresent Then colHeaders.Add vHeaders(1, I)
Next I
ReDim sRes(1 To colHeaders.Count)
For I = 1 To colHeaders.Count
sRes(I) = colHeaders(I)
Next I
Headers = Join(sRes, sDelimiter)
End Function
==========================================
You should probably add some logic to the routine to ensure your range arguments are a single row, and that the two arguments are of the same size.