第二章 算法与问题解决 知识点题库
则最后得到的字符串是：（ ）
空白矩形框中应该填入的是（ ）
Private Sub Command1_Click()
Dim sum As Double, x As Double
sum=0
n=0
For i=1 To 5
x=n/i
n=n+1
sum=sum+x
Next i
End Sub
该程序计算了一个表达式的值，这个表达式是（ ）
s=0
For i=1 To 10
t=1
for j=1 to i
t=t*j
next j
s=s+t
Next i
若流程执行时，输入x的值为13，那么输出的依次是（ ）
x=Val(Text1.Text)
If x>3 Then
If x<=6 Then y=2*x
Else y=3*x
Else
y=4*x
End If
Print y
若程序运行时在文本框Text1中输入6，则y的值是 （ ）
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（1） 实现上述功能的VB 程序如下，请在划线处填入合适代码。
Private Sub Command1_Click()
Dim n As Integer, L As Integer, t As Integer
Dim i As Integer, j As Integer, k As Integer
Dim s As String, result As String
Dim a(1 To 50) As Integer, dir(1 To 50) As Integer
L = Val(Text1.Text): n = Val(Text2.Text): t = Val(Text3.Text) s = Text4.Text
s = s + ".": tmp = 0: k=0
For i = 1 To Len(s)
ch = Mid(s, i, 1)
If ch >= "0" And ch <= "9" Then
tmp = tmp * 10 + Val(ch)
Else
k = k + 1
a(k) = tmp: dir(k) = 1
tmp = 0
End If
Next i
For i = 1 To t
For j = 1 To n
IfThen dir(j) = -dir(j)
Else
For c = 1 To n
IfThen dir(c) = (-1) * dir(c)
dir(j) = (-1) * dir(j)
End If
Next c
End If
Next j
Next i
For i = 1 To n
result = result + Str(a(i))
Next i
Label5.Caption = Str(t) + "秒后小球的位置为：" + result
End Sub
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（2） 若文本框Text3中输入的内容为“4”，单击“求解”按钮后，在标签框Label5中显示的结果为。
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（1） 观察界面，程序中未使用到的控件是（填字母：A ．
/B ． 
/ C ． 
/ D ． 
）
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（2） 根据题意，请将划线处代码补充完整。
Private Sub Command1_Click()
Dim zf As String, tmp As String
Dim s As String, i As Integer, ch As String
tmp = ""
s = ""
For i = 1 To Len(zf)
ch = Mid(zf, i, 1)
If ch >= "0" And ch <= "9" Then
ElseIf tmp <> "" Then
s = s + tmp + ","
tmp = ""
End If
Next i
Text2.Text = s
End Sub
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（3） 当输入的文本信息如图所示，若删除加框代码，则文本框Text2中显示的内容为。
Private Sub Command1_Click ( )
Dim t As Long, s As string
s = Text1. Text
For i = 1 To Len (s)
s = Mid(Text1. Text, i, 1)
If s > = “0” s < = “9” Then
t = t * 10 + Va1 (s)
ElseIF s > = “a” And s< = “z” Then
t = 10
End If
Next i
Text2. Text = Str(t)
End Sub
运行该程序，在文本框Text1中输入“2018 Iphone7”，单击命令按钮Command1后，文本框Text2中显示的内容是（ ）
s=0
For k=1 To 5
s=s * k
Next k
Print s
m = Int(Rnd * 4 + 2)
For i = 1 To 6 - m
For j = 1 To 6 - i
If a(j) - a(j + 1) < 0 Then
t = a(j): a(j) = a(j + 1): a(j + 1) = t
End If
Next j
Next i
数组元素a(1)到 a(6)的值依次为“49，45，5，61，42，71”，执行该程序段后，a(1)～a(6)各元素值不可能的是（ ）
a=98
b=63
r=a%b
while r!=0:
a=b
print('a的值是',a)
b=r
print('b的值是',b)
r=a % b
print('r的值是',r)
Dim a As Integer, b As Integer
a=Len（"China"）
b=a-2
If a Mod b=2 Then a=a^2 Else a=b^2
该程序段运行后，a的值为（ ）
关于异或，下列选择错误的是（ ）
