VBA:Iterate through all columns of a worksheet - vba

Question

Within the worksheet that the macro is defined in, id like to iterate through all the columns and save the ones that are filled in an array.
x = IIf(WorksheetFunction.CountA(Columns("C")) > 0, 1, 0)
This is an example of how I'd check if the column is empty. It returns 1 if the column is filled and 0 if it is empty.
Another thing that I'd like to know is how I could give and get the column name as a variable rather than hardcoded string ("C" as you see above).
Id like the array to look like:
("A", "B", "C", "E", "G", "H", "I")

Answer 1

This code should do the trick:
Dim DataCols() As String
Dim strTemp As String
Dim strCol As String
Dim i As Long
For i = 1 To ActiveSheet.UsedRange.Columns.Count
If WorksheetFunction.CountA(Columns(i)) > 0 Then
strCol = Columns(i).Address
strTemp = strTemp & Mid(strCol, 2, InStr(strCol, ":") - 2) & "|"
End If
Next i
strTemp = Left(strTemp, Len(strTemp) - 1) 'Trim trailing |
DataCols = Split(strTemp, "|")
The For..Next loop iterates through all columns in the active worksheet.
Using WorksheetFunction.CountA as you also used in your example it is then determined whether the current column has any data in it.
If the column contains data we get its address (Which will be a string in the format $A:$A) and use Mid(..) to get the letters between the $ character and the : character.
Append that column letter to strTemp, followed by a Pipe | which we will later use as a delimiter.
The Dynamic Array DataCols is then populated by using the Split function on strTemp to return a string array (delimited by the |s we included).
Hope this helps!