VBA检查单元格列中的字母，并在相应单元格中显示单词

Sub CheckLetters()
    Dim lastRow As Long
    Dim i As Long
    
    lastRow = Cells(Rows.Count, "A").End(xlUp).Row
    
    For i = 1 To lastRow
        Dim cellValue As String
        Dim word As String
        
        cellValue = Cells(i, "A").Value
        word = ""
        
        If IsNumeric(cellValue) Then
            word = "Number"
        ElseIf Len(cellValue) = 1 And Asc(UCase(cellValue)) >= 65 And Asc(UCase(cellValue)) <= 90 Then
            Select Case UCase(cellValue)
                Case "A"
                    word = "Apple"
                Case "B"
                    word = "Banana"
                Case "C"
                    word = "Cat"
                ' 添加更多字母和对应的单词
                ' Case "D"
                '     word = "..."
                ' Case "E"
                '     word = "..."
                ' ...
                Case Else
                    word = "Unknown"
            End Select
        Else
            word = "Invalid"
        End If
        
        Cells(i, "B").Value = word
    Next i
End Sub