Clear cells in a column of values if it has strings - excel

Question

Im trying to write / find a macro that when ran removes the value in a cell if the cells in the column is not a number. IE remove all the cells in column B if a string is found. I have this script to delete empty rows.
Was just trying to re write it so that it can delete the rows based on these condiitions
Sub RemoveRows()
Dim lastrow As Long
Dim ISEmpty As Long
lastrow = Application.CountA(Range("A:XFD"))
Range("A1").Select
Do While ActiveCell.Row < lastrow
ISEmpty = Application.CountA(ActiveCell.EntireRow)
If ISEmpty = 0 Then
ActiveCell.EntireRow.Delete
Else
ActiveCell.Offset(1, 0).Select
End If
Loop
End Sub

Answer 1

The code iterates backward from the last cell in column B and checks if the value in the cell is numeric using the IsNumeric() function.
If the value is not numeric then it deletes the entire row.
Note: looping backwards (ie. from the last row to first) is necessary when using a loop because the index gets shifted everytime a row gets deleted. Therefore, to avoid skipping some rows backward iteration is required.
Sub KeepOnlyNumbers()
Application.ScreenUpdating = False
Dim ws As Worksheet
Set ws = Sheets("Sheet1")
Dim i As Long
' iterating backwards (from last row to first to keep the logic flow)
For i = ws.Range("B" & ws.Rows.Count).End(xlUp).Row To 1 Step -1
' check whether the value is numeric
If Not IsNumeric(Range("B" & i)) Then
' if not numeric then clear the cells content
Range("B" & i).ClearContents
End If
Next i
Application.ScreenUpdating = True
End Sub

Answer 2

You can use IsNumeric to evaluate if an object can be evaluated as a number. So you can add:
If Not IsNumeric(ActiveCell) Then
ActiveCell.EntireRow.Delete
Else
ActiveCell.Offset(1, 0).Select
End If
to your Do While loop and it should do what you want. I haven't tested this; let me know if you get an error.

Answer 3

You do not have to iterate backwards even when deleting rows, you can do union and call delete/clear on the unioned range.
Sub UnionOnCondition()
Dim usedColumnB
Set usedColumnB = Intersect(ActiveSheet.UsedRange, _
ActiveSheet.Columns("b"))
If usedColumnB Is Nothing Then _
Exit Sub
Dim result: Set result = Nothing
Dim cellObject
For Each cellObject In usedColumnB
' skip blanks, formulas, dates, numbers
If cellObject = "" Or _
cellObject.HasFormula Or _
IsDate(cellObject) Or _
IsNumeric(cellObject) Then GoTo continue
If result Is Nothing Then
Set result = cellObject.EntireRow
Else
Set result = Union(result, cellObject.EntireRow)
End If
continue:
Next
If Not result Is Nothing Then _
result.Select ' result.Clear or result.Delete
End Sub