Private sub Command1_Click()

        Dim a As Single

        Dim py As String

             a= Val (Text1)  （1）

           If a>0 Then py =”正数”

           If a=0 Then py=”零”

           If a<0 Then py=”负数”

              Label3.Caption=a（2）

     End Sub

Private Sub Command1_Click()

  Dim a(0 To 5) As Integer

  Dim i As Integer               ’①

  a(0) = 1                      '②

  For i = 1 To 5

    a(i) = 2 * a(i - 1) + 1          '③

  Next i

  Text1.Text = Str(a(6))         '④

End Sub