VBA Merging Columns in Excel - excel

Question

I am trying to write a simple thing that will merge cells in excel with the same information. What I've got thus far is what follows:
Private Sub MergeCells()
Application.ScreenUpdating = False
Application.DisplayAlerts = False
Dim rngMerge As Range, cell As Range
Set rngMerge = Range("B2:B1000") 'Set the range limits here
Set rngMerge2 = Range("C2:C1000")
MergeAgain:
For Each cell In rngMerge
If cell.Value = cell.Offset(1, 0).Value And IsEmpty(cell) = False Then
Range(cell, cell.Offset(1, 0)).Merge
GoTo MergeAgain
End If
Next
Application.DisplayAlerts = False
Application.ScreenUpdating = True
For Each cell In rngMerge2
If cell.Value = cell.Offset(1, 0).Value And IsEmpty(cell) = False Then
Range(cell, cell.Offset(1, 0)).Merge
GoTo MergeAgain
End If
Next
Application.DisplayAlerts = False
Application.ScreenUpdating = True
End Sub
So the problem I'm encountering is split into two issues, First I'm trying to get this to work for columns A - AK but as you can see above I don't know how to combine it without just making it repeat the same thing 30 times over. Is there another way to group it.
Also when I assign the range to Range("AF2:AF1000") and Range("AG2:AG1000") then excel in its entirety crashes. I was hoping you all could help steer me into the right direction.

Answer 1

Repeat code inside a subroutine is a sign that some of the routines functionality should be extracted into its own method.
Performance
1000 seems like an arbitrary row: Range("B2:B1000"). This range should be trimmed to fit the data.
It is better to Union all the cells to be merged and merge them in a single operation.
Application.DisplayAlerts does not need to be set to True. It will reset after the subroutine has ended.
Public Sub MergeCells()
Dim Column As Range
Application.ScreenUpdating = False
With ThisWorkbook.Worksheets("Sheet1")
For Each Column In .Columns("A:K")
Set Column = Intersect(.UsedRange, Column)
If Not Column Is Nothing Then MergeEqualValueCellsInColumn Column
Next
End With
Application.ScreenUpdating = True
End Sub
Sub MergeEqualValueCellsInColumn(Target As Range)
Application.DisplayAlerts = False
Dim cell As Range, rMerge As Range
For Each cell In Target
If cell.Value <> "" Then
If rMerge Is Nothing Then
Set rMerge = cell
Else
If rMerge.Cells(1).Value = cell.Value Then
Set rMerge = Union(cell, rMerge)
Else
rMerge.Merge
Set rMerge = cell
End If
End If
End If
Next
If Not rMerge Is Nothing Then rMerge.Merge
End Sub

Answer 2

You keep modifying the cells in rngMerge but not the definition of it before reusing it. This would likely work better if you started at the bottom and worked up as the situation is similar to inserting or deleting rows.
Option Explicit
Private Sub MergeCells()
Dim i As Long, c As Long, col As Variant
Application.DisplayAlerts = False
'Application.ScreenUpdating = false
col = Array("B", "C", "AF", "AG")
For c = LBound(col) To UBound(col)
For i = Cells(Rows.Count, col(c)).End(xlUp).Row - 1 To 2 Step -1
If Cells(i, col(c)).Value = Cells(i, col(c)).Offset(1, 0).Value And Not IsEmpty(Cells(i, col(c))) Then
Cells(i, col(c)).Resize(2, 1).Merge
Cells(i, col(c)).HorizontalAlignment = xlCenter
Cells(i, col(c)).VerticalAlignment = xlCenter
End If
Next i
Next c
Application.DisplayAlerts = True
'Application.ScreenUpdating = True
End Sub
I've added a wrapping loop that cycles through multiple columns pulled from an array.
I've also notice the Private nature of the sub procedure and I'm guess that this is in a worksheet's private code sheet (right-click name tab, View Code). If the code is to be run on multiple worksheets, it belongs in a public module code sheet (in the VBE use Insert, Module) and proper parent worksheet references should be added to the Cells.

Answer 3

It appears you are running the same procedure on rngMerge and rngMerge2, and that they are the same size.
I suggest the following, where you just iterate through the columns, and then through the cells in each column:
Option Explicit
Private Sub MergeCells()
Application.ScreenUpdating = False
Application.DisplayAlerts = False
Dim rngMerge As Range, cell As Range
Dim rngFull As Range
Set rngFull = Range("B2:AK1000")
For Each rngMerge In rngFull.Columns
For Each cell In rngMerge.Cells
If cell.Value = cell.Offset(1, 0).Value And IsEmpty(cell) = False Then
Range(cell, cell.Offset(1, 0)).Merge
'Add formatting statements as desired
End If
Next cell
Next rngMerge
Application.DisplayAlerts = False
Application.ScreenUpdating = True
End Sub
NOTE As written, this will only handle duplicates. If you have triplets or more, only pairs of two will be combined.

Answer 4

I would frame the problem a bit differently. Your code goes through each cell in the range, compares it to the next cell, and, if the values of the two are equivalent, then merge them together. I think it a bit clearer to check each cell against the previous cell value instead.
Also, you can iterate over the columns in order to avoid code repetition (as mentioned in other answers).
Sub MergeCells()
Dim wks As Worksheet
Dim mergeRange As Range
Dim column As Range
Dim cell As Range
Dim previousCell As Range
'Because the Sheets property can return something other than a single worksheet, we're storing the result in a variable typed as Worksheet
Set wks = Sheets("Sheet1")
'To run this code across the entire "used part" of the worksheet, use this:
Set mergeRange = wks.UsedRange
'If you want to specify a range, you can do this:
'Set mergeRange = wks.Range("A2:AK1000")
For Each column In mergeRange.Columns
For Each cell In column.Cells
If cell.Row > 1 Then
'cell.Offset(-1) will return the previous cell, even if that cell is part of a set of merged cells
'In that case, the following will return the first cell in the merge area
Set previousCell = cell.Offset(-1).MergeArea(1)
If cell.Value = previousCell.Value And Not IsEmpty(cell) Then
cell.Value = ""
wks.Range(previousCell, cell).Merge
End If
End If
Next
Next
End Sub
If you want to run this code on multiple ranges, you can isolate the code which carries out the merges within a range, into its own Sub procedure:
Sub MergeCellsInRange(mergeRange As Range)
For Each column In mergeRange.Columns
For Each cell In column.Cells
If cell.Row > 1 Then
Set previousCell = cell.Offset(-1).MergeArea(1)
If cell.Value = previousCell.Value And Not IsEmpty(cell) Then
cell.Value = ""
wks.Range(previousCell, cell).Merge
End If
End If
Next
Next
End Sub
and call it multiple times from your main procedure:
Sub MergeCells()
Dim wks As Worksheet
Dim mergeRange As Range
Dim column As Range
Dim cell As Range
Dim previousCell As Range
Set wks = Sheets("Sheet1")
MergeRange wks.Range("A2:U1000")
MergeRange wks.Range("AA2:AK1000")
End Sub
References:
Excel object model
Global Sheets property, Sheets collection
Worksheet object
UsedRange property
Range object
Cells property
Row property
Offset property
MergeArea property
Value property
VBA
For Each ... In construct
IsEmpty function
Dim statement
Set statement
Sub statement