How to hide rows in VBA based on values in row, quickly - excel

Question

this is my first time using the site, so forgive me for any inept explaining. I have a working macro to hide/unhide rows based on content of the rows, I just want it to be faster. Using a check box, when the box is checked, all rows with an "x" in column D get unhidden, those without an "x" get hidden. Same thing happens when it is unchecked, except it references column C, not D.
Right now, this code works. It's just a little slower than I'd like, since I'm sharing this with a bunch of people. Any ideas for how to speed it up? I'm pretty darn new to VB (the internet is astoundingly wise and a good teacher), but that doesn't matter. I already improved the code - before it selected each row, then referenced the column, and it was awful. Any ideas to speed it up (preferably without moving the screen) would be great.
Thanks so much folks,
DS
Sub NewLuxCheck()
Dim x As Integer
NumRows = Range("A42", "A398").Rows.Count
Range("A42").Select
If ActiveSheet.Shapes("checkbox2").OLEFormat.Object.Value = 1 Then
For x = 42 To NumRows + 41 Step 1
If Worksheets("Base").Range("D" & x).Value = "x" Then
Worksheets("Base").Range(x & ":" & x).EntireRow.Hidden = False
Else
Worksheets("Base").Range(x & ":" & x).EntireRow.Hidden = True
End If
Next
Else
For x = 42 To NumRows + 41 Step 1
If Worksheets("Base").Range("C" & x).Value = "x" Then
Worksheets("Base").Range(x & ":" & x).EntireRow.Hidden = False
Else
Worksheets("Base").Range(x & ":" & x).EntireRow.Hidden = True
End If
Next
End If
MsgBox ("Done")
End Sub

Answer 1

You could use array formula and let Excel to return array with row-numbers where 'x' value occures. It will be quicker but you'll have to reorganise your code and create separate functions etc.
Here example where array formula finds rows whre in column 'D' the cell has value 'x'. Then string of this row numbers is created in form of "A1,A5,A10" ...means 'x' was found in rows 1,5,10. And finally Range(rowsJoind).EntireRow.Hidden is used for all the rows to be hidden/un-hidden in one step.
For rows with value different then 'x' you'll have to use formula like '=IF({0}<>""x"", ROW({0}), -1)'.
Sub test()
Dim inputRange As Range
Dim lastRow As Long
Dim myFormula As String
Dim rowsJoined As String, i As Long
Dim result As Variant
With Worksheets("Base")
lastRow = .Range("D" & .Rows.Count).End(xlUp).Row
Set inputRange = .Columns("D").Resize(lastRow)
Application.ReferenceStyle = xlR1C1
myFormula = "=IF({0}=""x"", ROW({0}), -1)"
myFormula = VBA.Strings.Replace(myFormula, "{0}", inputRange.Address(ReferenceStyle:=xlR1C1))
result = Application.Evaluate(myFormula)
result = Application.Transpose(result)
Application.ReferenceStyle = xlA1
For i = LBound(result) To UBound(result)
If (result(i) > -1) Then
rowsJoined = rowsJoined & "A" & result(i) & IIf(i < UBound(result), ",", "")
End If
Next i
.Range(rowsJoined).EntireRow.Hidden = False
End With
End Sub