How to auto fill column down in VBA - excel

Question

How can I auto fill a column down, e.g., Cell(A1).value = dog and Cell(A12).value = Pen
How do I fill down A2:A11 with the value = dog and the A13 value = pen without manually selecting the column?
Sub filldown_example()
Dim missingcells as range
Dim fillsedcells as range
Set missingcells = select
For each filledcells in missingcells
If filledcells = "" Then
filledcells.filldown
End If
Next filledcells
End sub

Answer 1

No need to loop here.
Sub fillit()
With Range("a1:a13")
.SpecialCells(xlCellTypeBlanks).FormulaR1C1 = "=R[-1]C"
.Value = .Value 'formula to value
End With
End Sub

Answer 2

You do not need VBA for this. If you search Google for Excel fill all blanks with cell above you will get the non-VBA method.
If you still want VBA, then try this. You do not need to loop through all cells.
Code:
Option Explicit
Sub Sample()
Dim ws As Worksheet
Dim lRow As Long
Dim rng As Range
'~~> Change this to the relevant sheet
Set ws = Sheet1
With ws
'~~> Find the last row in Col A and add 1 to it
lRow = .Range("A" & .Rows.Count).End(xlUp).Row + 1
'~~> Find the blank cells
On Error Resume Next
Set rng = .Range("A1:A" & lRow).SpecialCells(xlCellTypeBlanks)
On Error GoTo 0
'~~> Add the formula to get values from the above cell in 1 go
If Not rng Is Nothing Then rng.FormulaR1C1 = "=R[-1]C"
'~~> Convert formulas to values
.Range("A1:A" & lRow).Value = .Range("A1:A" & lRow).Value
End With
End Sub
In Action:

Answer 3

Fill Down Selection
This will allow you to select multiple ranges with multiple columns to fill down each of them.
Range
Sub FillDownSelectionRange()
If TypeName(Selection) <> "Range" Then Exit Sub
Dim rg As Range: Set rg = Selection
Dim arg As Range ' Area Range
Dim crg As Range ' Column Range
Dim rCell As Range ' Row Cell Range
Dim rValue As Variant
For Each arg In rg.Areas
For Each crg In arg.Columns
If crg.Rows.Count > 1 Then
For Each rCell In crg.Cells
If Len(CStr(rCell.Value)) = 0 Then
rCell.Value = rValue
Else
If rCell.Value <> rValue Then
rValue = rCell.Value
End If
End If
Next rCell
End If
rValue = Empty
Next crg
Next arg
End Sub
Array
To speed up, instead of looping through the cells, you could loop through an array.
Sub FillDownSelectionArray()
If TypeName(Selection) <> "Range" Then Exit Sub
Dim rg As Range: Set rg = Selection
Dim arg As Range ' Area Range
Dim crg As Range ' Column Range
Dim cData As Variant ' Column Array
Dim rValue As Variant
Dim r As Long
For Each arg In rg.Areas
For Each crg In arg.Columns
If crg.Rows.Count > 1 Then
cData = crg.Value
For r = 1 To UBound(cData, 1)
If IsEmpty(cData(r, 1)) Then
cData(r, 1) = rValue
Else
If cData(r, 1) <> rValue Then
rValue = cData(r, 1)
End If
End If
Next r
crg.Value = cData
End If
rValue = Empty
Next crg
Next arg
End Sub