Remove last comma from a cell in a dynamic range - excel

Question

I'm trying to delete the last comma from each cell of a dynamic range.
The macro doesn't delete the comma, it just selects the range.
Sub selecting()
Dim sht As Worksheet
Dim LastColumn As Long
Dim StartCell As Range
Set sht = Worksheets("Sheet1")
Set StartCell = Range("D1")
'Find Last Row and Column
LastRow = sht.Cells(sht.Rows.Count, StartCell.Column).End(xlUp).row
LastColumn = sht.Cells(StartCell.row, sht.Columns.Count).End(xlToLeft).Column
'Select Range
sht.Range(StartCell, sht.Cells(LastRow, LastColumn)).Select
With ActiveCell
If Right(.Value, 1) = "," Then .Value = Right(.Value, Len(.Value) - 1)
End With
End Sub
Here is what is returned

Answer 1

Since you want to remove the last character from each cell in column D, try this variation on braX's comment. It loops trough each used cell in column 4 and deletes the last character.
With ThisWorkbook.Sheets("Sheet1")
For Each cel In .Range("D1", .Cells(.Rows.Count, 4).End(xlUp))
cel.Value = Left(cel, Len(cel) - 1)
Next cel
End With

Answer 2

The most conventional way would be to loop over your cells:
Sub Replacing()
Dim lr As Long, lc As Long
Dim rng As Range, cl As Range
With Worksheets("Sheet1")
'Find Last Row and Column
lr = .Cells(.Rows.Count, 1).End(xlUp).Row
lc = .Cells(1, .Columns.Count).End(xlToLeft).Column
'Go through range
Set rng = .Range(.Cells(1, lc), .Cells(lr, lc))
For Each cl In rng
If Right(cl.Value, 1) = "," Then cl.Value = Left(cl.Value, Len(cl.Value) - 1)
Next cl
End With
End Sub
Better would be to go through memory if your range is actually much larger (for performance sake)
Sub Replacing()
Dim lr As Long, lc As Long, x As Long
Dim arr As Variant
With Worksheets("Sheet1")
'Find Last Row and Column
lr = .Cells(.Rows.Count, 1).End(xlUp).Row
lc = .Cells(1, .Columns.Count).End(xlToLeft).Column
'Go through array
arr = .Range(.Cells(1, lc), .Cells(lr, lc)).Value
For x = LBound(arr) To UBound(arr)
If Right(arr(x, 1), 1) = "," Then arr(x, 1) = Left(arr(x, 1), Len(arr(x, 1)) - 1)
Next x
'Write array back to range
.Range(.Cells(1, lc), .Cells(lr, lc)).Value = arr
End With
End Sub
And a more less conventional way (alright for small ranges I guess) would be to evalate a range and avoid an iteration. This however comes at the cost of an array formula:
Sub Replacing()
Dim lr As Long, lc As Long
Dim rng As Range
With Worksheets("Sheet1")
'Find Last Row and Column
lr = .Cells(.Rows.Count, 1).End(xlUp).Row
lc = .Cells(1, .Columns.Count).End(xlToLeft).Column
'Evaluate your range
Set rng = .Range(.Cells(1, lc), .Cells(lr, lc))
rng.Value = .Evaluate("IF(RIGHT(" & rng.Address & ",1)="","",LEFT(" & rng.Address & ",LEN(" & rng.Address & ")-1)," & rng.Address & ")")
End With
End Sub

Answer 3

Use the Replace() function:
For Each Cell in Range.Cells
Cell.Value = Replace(Cell.Text, ",", "")
Next Cell
Edit: After testing, replaced .Text with .Value
Edit 2: I'd also like to add, why are you selecting the range? My supposition is that you are selecting it to enable use of ActiveCell but you can simply manipulate the range without selecting it. Selecting the range is asking to incur errors. My suggestion is:
Dim rplcRng as Range
Set rplcRange = sht.Range(StartCell, sht.Cells(LastRow, LastColumn))
For Each Cell in rplcRng.Cells
Cell.Value = Replace(Cell.Text, ",", "")
Next Cell
Edit 3: added "s"s