Vba获取不知道数据范围，找到J列，判断j列中是否存在空的单元格，如果有，就写入当天日期和时间

Sub CheckJColumn()
Dim lastRow As Long
Dim jColumn As Range
Dim cell As Range

'获取最后一行
lastRow = Cells(Rows.Count, 1).End(xlUp).Row

'获取J列
Set jColumn = Range("J1:J" & lastRow)

'遍历J列中的单元格
For Each cell In jColumn
'判断单元格是否为空
If cell.Value = "" Then
'写入当天日期和时间
cell.Value = Format(Date, "yyyy/mm/dd") & " " & Format(Time, "hh:mm:ss")
End If
Next cell
End Sub