n = 0

For i = 1 To Len(Text1.Text)

    c = Mid(Text1.Text, i, 1)

    If c >= "0" And c <= "9" Then m = 1 Else m = 2

    a(m) = a(m) + 1

    If a(m) = 1 Then n = n + 1

Next i

数组a各元素的初始值都为0，文本框Textl的内容为“Luck2018”。执行程序后，变量n的值为{#blank#}1{#/blank#}

Private Function f(x As Single, n As Integer) As Single

  If n ＝0 Then

    f ＝1

  Else

    If n Mod 2 ＝1 Then

      f＝x * f(x, n\2)

    Else

      f＝f(x, n\2) \x

    End If

  End If

End Function

Private Sub Command1_Click()

  Label1.Caption＝Str(f(4, 6))

End Sub

程序运行时，单击按钮Command1，标签Label1显示的内容是（  ）

Private Sub Text1_Change()

  Dim c As Integer, i As Integer

  i=0

  c = Val(Text1.Text)

  Do While c >= 0

    c = c - i

    i = i + 1

  Loop

  Text1.Text = Str(c)

End Sub

在文本框输入“6”，执行该程序段后， 其中c >= 0执行的次数是（  ）

i = n

Do While i >=2

k = i

For j =            To 1 Step -1

If a(j) > a(k) Then k = j

Next j

If i <> k Then

t = a(k): a(k) = a(i): a(i) = t

End If

Loop

则下列说法正确的是(  )

Private Sub Command1_Click()

    Dim a As Integer, b As Integer

    Dim c As Integer                     '①

    a= Val(Text1. Text)                     '②

    b = Val(Text2. Text)

    c=a + b                             '③

    Label1. Caption ="a + b="+c        '④

End Sub