VBA Looping through single row selections and executing concat code - vba

Question

So, I've been scratching my head for a couple of hours now trying to figure this out. No matter where I look and what I do, I can't seem to make it work.
I have an excel document with ~20 columns and a completely variable number of rows. I want to concatenate each adjacent cell within the defined width (columns A:V)into the first cell (A1 for the first row), and then move to the next row and do the same until I get to the bottom. Snippet below:
Example before and after I'm trying to make
I have the code that does the concatenation. To make it work I have to select the cells I want to concatenate (A1:V1), and then execute the code. Even though some cells are blank, I need the code to treat them this way and leave semicolons there. The code works exactly as I need it to, so I've been trying to wrap it in some sort of Range select, offset, loop:
Dim c As Range
Dim txt As String
For Each c In Selection
txt = txt & c.Value & ";"
Next c
Selection.ClearContents
txt = Left(txt, Len(txt) - 2)
Selection(1).Value = txt
What I am struggling with is making the selection A1:V1, running the code, and then looping this down to A2:V1, A3:V3, etc. I think this can be done with a loops and an offset, but I cannot for the life of me work out how.
Any help at all would be much appreciated :)

Answer 1

This uses variant Arrays and will be very quick
Dim rng As Range
With Worksheets("Sheet4") 'change to your sheet
'set the range to the extents of the data
Set rng = .Range(.Cells(1, 1), .Cells(.Rows.Count, 22).End(xlUp))
'Load data into an array
Dim rngArr As Variant
rngArr = rng.Value
'create Out Bound array
Dim OArr() As Variant
ReDim OArr(1 To UBound(rngArr, 1), 1 To 1)
'Loop array
Dim i As Long
For i = LBound(rngArr, 1) To UBound(rngArr, 1)
'Combine Each Line in the array and load result into out bound array
OArr(i, 1) = Join(Application.Index(rngArr, i, 0), ";")
Next i
'clear and load results
rng.Clear
rng.Cells(1, 1).Resize(UBound(OArr, 1)).Value = OArr
End With

Answer 2

Here's a quick little script I made up to do this - the main thing to note is that I don't use selection, I used a defined range instead.
Sub test()
Dim i As Long
Dim target As Range
Dim c As Range
Dim txt As String
For i = 3 To 8
Set target = Range("A" & i & ":C" & i)
For Each c In target
txt = txt & c.Value & ";"
Next c
Cells(i + 8, "A").Value2 = Left$(txt, Len(txt) - 1)
txt = ""
Next i
End Sub

Answer 3

Just change the range on the below to your requirements:
Sub concat_build()
Dim buildline As String
Dim rw As Range, c As Range
With ActiveSheet
For Each rw In .Range("A2:V" & .Cells(.Rows.Count, "B").End(xlUp).Row + 1).Rows
buildline = ""
For Each c In rw.Cells
If buildline <> "" Then buildline = buildline & ";"
buildline = buildline & c.Value2
Next
rw.EntireRow.ClearContents
rw.EntireRow.Cells(1, 1) = buildline
Next
End With
End Sub