Clear content of cell A2 if A2 value same with A1 - vba

Question

I have lists of different value in column A and B which contents same value for several rows respectively. like the following:
BEFORE
column A | column B
1. a b
2. a b
3. a b
4. a b
5. z z
6. z z
7. z z
8. z z
AFTER
column A | column B
1. a b
2.
3.
4.
5. z z
6.
7.
8.
How do I delete the duplicate cell with former rows cell in same column? Like the After.
I have done the following so far:
Sub clear()
Dim x
Dim c
x = 1
c = Range("a1").Value
Do Until Cells(x, 1) = ""
If Cells(x, 1) = Cells(x + 1, 1) Then
Cells(x + 1, 1) = Range().ClearContents
End If
Loop
End Sub

Answer 1

Try this:
Option Explicit
Sub clear()
Dim cRow As Long
Dim CellValue As String
cRow = 2 ' start the loop in row 2
CellValue = Range("a1").Value
Do Until Cells(cRow, 1) = ""
If Cells(cRow, 1) = CellValue Then
Cells(cRow, 1).ClearContents
Cells(cRow, 2).ClearContents ' clear column B cell
Else
CellValue = Cells(cRow, 1) ' when the cell value changes,
End If
cRow = cRow + 1 ' increment the row number so the next loop goes to the next row
Loop
End Sub
I prefer variables with descriptive names over x and c.
Some issues with your code were:
Range must have a parameter, but you don't need Range when you already have the cell object with Cells()
you did not increment the variable that sets the row
the cleared cell became the new current cell and since it had just been cleared, the loop would end
you never used the c variable, but it is useful to keep a record of the comparison string.

Answer 2

you may want to consider the following "array" approach should speed be an issue:
Option Explicit
Sub main()
Dim i As Long, j As Long
Dim myArr As Variant, refVal As Variant
With Worksheets("MySheet") '<--| change "MySheet" with your actual sheet name
With Intersect(.UsedRange, .Columns("A:B")) '<--| consider only columns A and B rows down to the worksheet used range last one
myArr = .Value ''<--| store values in array
For j = LBound(myArr, 2) To UBound(myArr, 2) '<--| loop through array columns
refVal = myArr(1, j) '<--| get column fiurst reference value
For i = LBound(myArr, 1) + 1 To UBound(myArr, 1) '<--| loop through form current column 2nd row downwards
If myArr(i, j) = refVal Then '<--| if there's a duplicate...
myArr(i, j) = "" '<--| ...erase it
Else '<--| otherwise...
refVal = myArr(i, j) '<--| ... get the new non duplicate value as the reference one
End If
Next i
Next j
.Value = myArr '<--| write back array to worksheet
End With
End With
End Sub
using Option Explicit statement is a safe habit that at the cost of some little extra work to declare all variables pays you back with much more control over your code and much less issues in debugging and maintaining it
using full range reference (like Worksheets("MySheet").Range(...)) is a good habit to avoid issues due to user sheet jumping selections

Answer 3

To complement the answers from teylyn and user3598756, you could work from bottom to top to check the values:
Public Sub myClear(Optional ByRef wks As Worksheet = Nothing)
Dim c As Range
Dim col As Long
If wks Is Nothing Then Set wks = ActiveSheet
For col = 1 To 2 'Columns A and B
Set c = wks.Cells(wks.Rows.Count, col).Rows.End(xlUp)
Do While c.Row > 1
If c.Value = c.Offset(-1, 0).Value Then c.ClearContents
Set c = c.Offset(-1, 0)
Loop
Next col
End Sub
The sub will work by default on the ActiveSheet, but you can give in parameter the actual sheet you want to work on.