小王编写的“模拟撤销”VB程序如下,文本框 Text1中的内容是撤销前字符串,文本概Text2中的内容是历史记录,单击“撤销”按钮Command1后,在标签Label1中显示撤销过程,程序运行界面如由下图所示。
(1)实观上述功能的VB程序如下,在程序中出现的对象没有Caption属性的是______ 。(选填,填字码:
A.Label1 | B.Command1 | C.Text1和Text2) |
Private Sub Command1_Click()
Dim s As String, t As String, ch As String
Dim c As String, num As String, ss As String
Dim n As Integer, i As Integer
s = Text1.Text: t = Text2.Text
c = "": num = "": ss = s
For i = Len(t) To 1 Step -1
___________________
If ch >= "a" And ch <= "z" Or ch >= "A" And ch = "Z" Then
c = ch + c
ElseIf ch >= "0" And ch <= "9" Then
num = ch + num
Else
n = Val(num)
If ch = "-" Then
s = Mid(s, 1, n - 1) + ____________________________
Else
s = Mid(s, 1, n - 1) + Mid(s, n + Len(c), Len(s) - n - Len(c) + 1)
End If
ss = ss + "→" + s
c = "": num = ""
End If
Next i
Label1.Caption = ss
End Sub
(3)运行该程序,若文本框Text1中的内容是“April”,文本框Text2中的内容是“-3p+3ri-6e”,单击撤销按钮,For循环语句执行完成后,字符串s的值是_____________。
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2