Author: admin

Here are two functions that I will be using in an upcoming sheet, I want to explain them briefly and add them to my small library (file is downloadable at the end of this post).

The names hint at the purpose: given a value to match, they will return the number of the row or column the value was found in, or zero if it wasn’t found at all. The concept is similar to the “vlookup” formula, but performance for these two functions is terrible by comparison and for that reason I don’t recommend using them repetitively in a loop or with large columns of data. I maintain several files with built-in functionality where most of the user input comes from cells in a sheet but I can’t always guarantee the position of those cells – that’s where these two come in handy. Instead of hard-coding the cell address, these functions can find the address by matching the value in that cell which allows you to modify the user-facing sheet without having to update code every time; it also makes the sheet somewhat tolerant of being rearranged by the user, but you need to be careful in case it’s been mangled in such a way that the inputs are found but are totally bogus.

getRowNum()

Function getRowNum(findValue As Variant, Optional sheetName As String, Optional colNum As Long) As Long
'by Elliot 8/9/20 www.elliotmade.com
'this function will return the row number in the first (or specified) column that matches the "findValue" parameter
'this is similar to vlookup, but not as fast or performant
'an example use is to get an input from a sheet where you can't guarantee the position of the cell
'combine this with getColNum() to find a cell value where a known column heading and row label intersect
'****** this requires the "getlastrow" function *******

Dim i As Long
Dim lastRow As Long

Dim j As Long
If sheetName <> "" Then
    For j = 1 To Worksheets.Count
        If Worksheets(j).Name = sheetName Then GoTo sheetOK
    Next j
    GoTo abort 'specified sheet name was not found
sheetOK:
End If

'default values for optional parameters
If sheetName = "" Then sheetName = ActiveSheet.Name
If colNum = 0 Then colNum = 1

lastRow = getLastRow(sheetName, colNum)

For i = 1 To lastRow
    If Worksheets(sheetName).Cells(i, colNum).Value2 = findValue Then
        getRowNum = i
        GoTo found
    End If
Next i

found:
abort:

End Function

getColNum()

Function getColNum(findValue As Variant, Optional sheetName As String, Optional rowNum As Long) As Long
'by Elliot 8/9/20 www.elliotmade.com
'this function will return the column number in the first (or specified) column that matches the "findValue" parameter
'this is similar to vlookup, but inverted not as fast or performant
'an example use is to get an input from a sheet where you can't guarantee the position of the cell
'combine this with getRowNum() to find a cell value where a known column heading and row label intersect
'****** this requires the "getLastCol" function *******

Dim i As Long
Dim lastCol As Long

Dim j As Long
If sheetName <> "" Then
    For j = 1 To Worksheets.Count
        If Worksheets(j).Name = sheetName Then GoTo sheetOK
    Next j
    GoTo abort 'specified sheet name was not found
sheetOK:
End If

'default values for optional parameters
If sheetName = "" Then sheetName = ActiveSheet.Name
If rowNum = 0 Then rowNum = 1

lastCol = getLastCol(sheetName, rowNum)

For i = 1 To lastCol
    If Worksheets(sheetName).Cells(rowNum, i).Value2 = findValue Then
        getColNum = i
        GoTo found
    End If
Next i

found:
abort:

End Function

The usage for both of these is simple, just give them a value to match, and if you want to search in a different row/column or a different sheet use the optional parameters. Note that these both rely on two functions I posted previously – getLastRow() and getLastCol(), both of which are included in the file below as well.

Building on the previous posts getLastRow() and getLastCol(), here is an example application of those techniques.

There are many ways to have alternating background color on rows in Excel: there’s a built-in option if you are working with a table, you can use conditional formatting with a formula, or add a helper column to filter and highlight manually. I find that having the color alternate on every single row doesn’t always suit the data I am working with however – often I would rather have the color change help me identify changes in one or more columns that are sorted so I can notice where one chunk ends and another begins.

This macro considers the content of the column(s) that are selected and alternates the background color each time it changes. This is probably easier to understand in a picture, so here we go:

The concept is simple: starting from the top, every time the contents of the selected column differ from the row above, that group of cells will either be highlighted or left alone. I designed this so that multiple columns could be selected – in the animation above you can see at first when only column A is selected that there are three highlighted groups, but when A:C is selected that there are six groups of rows.

If only a range of cells are selected rather than an entire column, the highlighting will be confined to those rows. When the entire column is selected it will only extend to the last used row and ignore the blanks at the bottom of the sheet – this is where the getLastRow() function comes into play. Additionally, the highlighted area stretches from column A to the last used column – found with the getLastCol() function.

The Code

Sub colorBands()

'highlight a range that contains the changing values to higlight by
'the range from column A to the last column will be alternatingly highlighted
'not intended for non-continuous selections

Dim s As Worksheet
Set s = ActiveSheet

Dim startRowNum As Long
Dim endRowNum As Long 'if the whole column is selected, only higlight to the last used row
Dim startColNum As Long
Dim endColNum As Long
Dim prevValue As Variant
Dim values As Variant 'the whole set will be added to an array for comparison
Dim startRows As Variant 'each set of rows will have a start and end in an array
Dim endRows As Variant
Dim rowOffset As Long 'difference between the row number and the counter variables
Dim colOffset As Long
Dim rowCount As Long
Dim colCount As Long
Dim lastCol As Long
Dim i As Long
Dim j As Long
Dim k As Long
Dim m As Long 'skip L because it's hard to differentiate from i
Dim n As Long
Dim tempValue As Variant
Dim highlight As Boolean

ReDim values(1 To 1)

'find the boundaries of the selection
endColNum = getLastCol()
endRowNum = getLastRow()
startColNum = Selection.Column
startRowNum = Selection.row
endColNum = startColNum + Selection.Columns.Count - 1
If startRowNum + Selection.Rows.Count < endRowNum Then endRowNum = startRowNum + Selection.Rows.Count - 1 'reset the row limit to highlight if the selection doesn't reach the end of the data in that column
rowOffset = startRowNum - 1
colOffset = startColNum - 1
rowCount = endRowNum - startRowNum + 1
colCount = endColNum - startColNum + 1
lastCol = getLastCol(, startRowNum)

'Some output for troubleshooting
Debug.Print "Starting Column: " & startColNum
Debug.Print "Ending Column: " & endColNum
Debug.Print "Starting Row: " & startRowNum
Debug.Print "Ending Row: " & endRowNum
Debug.Print "Offset from row 1 by: " & rowOffset
Debug.Print "Row Count: " & rowCount
Debug.Print "Column Count: " & colCount

'add the values to an array
If startColNum = endColNum Then
    For i = 1 To rowCount
        ReDim Preserve values(1 To i)
        values(i) = s.Cells(i + rowOffset, startColNum).Value
    Next i
Else
    For i = 1 To rowCount
        ReDim Preserve values(1 To i)
        For j = 1 To colCount
            tempValue = tempValue & s.Cells(i + rowOffset, j + colOffset).Value
        Next j
        values(i) = tempValue
        tempValue = Empty
    Next i
End If

'define the ranges that need to be higlighted
ReDim startRows(1 To 1)
ReDim endRows(1 To 1)
startRows(1) = startRowNum

m = 1
highlight = False
For k = 2 To rowCount
    If values(k) <> values(k - 1) Then 'this row is different from the previous, so it should start or end a higlighted area
        If highlight = False Then 'start a highlighted area
            ReDim Preserve startRows(1 To m)
            ReDim Preserve endRows(1 To m)
            highlight = True
            startRows(m) = k
        Else                    'end a highlighted area
            highlight = False
            endRows(m) = k - 1
            m = m + 1
        End If
    End If
Next k

If highlight = True Then endRows(m) = endRowNum - rowOffset 'close the last range if it's dangling

'Highlight each block
For n = 1 To UBound(startRows)
    s.Range(s.Cells(startRows(n) + rowOffset, 1), s.Cells(endRows(n) + rowOffset, lastCol)).Interior.ColorIndex = 4 'change this for a different color
Next n

End Sub

How to use it

In order to use this, I recommend adding it to your personal.xlsb file and mapping it to a button in the toolbar or a keyboard shortcut. The two functions getLastRow() and getLastCol() are also required, so those will also have to be added to the file. As I write more of these shared functions I will keep a single file up to date here to make this installation easier (link directly below).

Tips

• Save frequently, particularly before executing a macro. You cannot undo a macro, if something goes wrong you could lose work.
• Clear existing background colors before using this
• Change the color to something other than green if you prefer
• Avoid using this while filtered or with discontinuous selections, or you may get unexpected results
• This isn’t optimized for performance in any way, so be wary when using it on something large for the first time. For 50k rows it took ~5 seconds on my machine.

Similar to my previous post on finding the last used row in a sheet, this is a function that can be used to find the last used column. These two functions work nicely together to limit a loop or define a range when the source data may vary in size.

The function: getLastCol():

• If called with no parameters, the last used column in the active worksheet will be returned.
• The optional sheetName parameter lets you reference a sheet other than the one that is active.
• The optional rowNum parameter returns the last used column in a particular row.
• The optional colLimit parameter limits the total number of iterations in the loop when searching for the last used column, this can be used to speed up execution when you have an idea of what the sheet may contain already.
• If there is an error with the parameters it will return zero

Examples:

getLastCol() = 3
getLastCol("Fruit") = 3
getLastCol(,3) = 2 'last used column on row 3 only
getLastCol(Vegetables) = 0 'this sheet name does not exist

The Code:

Function getLastCol(Optional sheetName As String, Optional rowNum As Long, Optional colLimit As Long) As Long
'by Elliot 7/22/20 www.elliotmade.com
'this function will return the last used column on a sheet in a single row
'if no sheet name is specified it will use the active sheet
'if no row is specified it will find the last column in any row up to an optional limit (for faster performance)
'two assumptions are made: the file type is .xlsx or similar that supports 16k columns
'and the sheet is in the active workbook
'a zero returned means that there was a failure

Dim i As Long
Dim j As Long
Dim curLastCol As Long

'check for valid inputs first, return zero if there is a problem
If rowNum < 0 Or rowNum > 1048575 Then GoTo abort

If sheetName <> "" Then
    For i = 1 To Worksheets.Count
        If Worksheets(i).Name = sheetName Then GoTo sheetOK
    Next i
    GoTo abort 'specified sheet name was not found
sheetOK:
End If

If colLimit = 0 Then
    colLimit = 16384
ElseIf colLimit < 0 Or colLimit > 16384 Then
    GoTo abort
End If

If sheetName = "" Then sheetName = ActiveSheet.Name

'if no problem, find the last column
If rowNum = 0 Then
    getLastCol = Worksheets(sheetName).Cells(1, 16384).End(xlToLeft).Column
    For j = 1 To colLimit
        If Worksheets(sheetName).Cells(1048575, j).End(xlUp).Row > 1 Then curLastCol = j
        If curLastCol > getLastCol Then getLastCol = curLastCol
    Next j
Else
    getLastCol = Worksheets(sheetName).Cells(rowNum, 16384).End(xlToLeft).Column
End If

abort:

End Function

You may notice that the method using xlToLeft is used to find the last column in a specific row, but I did not use it when searching for the last column in the entire sheet; to do this in a loop would require iterating through every single row (over 1M!) and would take a significant amount of time. I chose to do two things to shortcut this process: first, check the first row because it often has headings for the rest of the document, and second, find the last used row in every column instead. This limits the possible trips through the loop to 16k at most (the number of columns in a sheet). I have some other ideas to improve on this, but I’ll leave it alone for now until it becomes a bottleneck.

Next I’ll post an example that puts this function to use, stay tuned.