VB_填空练习答案.doc

一.选择结构
'-------------------------------------------------------
'功能：用输入对话框输入x，根据如图公式计算对应的y，在窗体上输出y的值。
'-------------------------------------------------------
Private Sub Command1_Click()
'**********SPACE**********
Dim x As Single, 【?】 As Single
'**********SPACE**********
x = Val(【?"Please input x :", "输入X的值"))
If x = 10 Then
'**********SPACE**********
【?】
ElseIf x > 10 Then
'**********SPACE**********
y = Sqr(x) 【?】
Else
y = 2 * x ^ 3 + 6
End If
Print y
End Sub
(答案) Y InputBox y = 0 + Sin(x)

'-
'功能：下面的事件过程判断文本框Text1中输入的数所在区间，并在文本框Text2中输出判断结果
'-------------------------------------------------------
Private Sub Command1_Click()
Dim int1 As Integer
'**********SPACE**********
【?】 = Val(Text1.Text)
Select Case int1
Case 0
Text2.Text = "值为0"
'**********SPACE**********
Case 【?】
Text2.Text = "值在1和10之间（包括1和10）"
'**********SPACE**********
Case Is > 【?】
Text2.Text = "值大于10"
Case Else
Text2.Text = "值小于0"
End Select
End Sub
(答案1) int1 1 To 10 10

二.一般
'-------------------------------------------------------
'功能：本程序功能为，第一次单击窗体，Form1的输出结果为 2 5 9
'-------------------------------------------------------
Private Function sum(n As Integer)
'**********SPACE**********
【?】 j As Integer
j = j + n + 1
sum = j
End Function
Private Sub Form_Click()
Dim i%, s%
'**********SPACE**********
For 【?】 = 1 To 3
'**********SPACE**********
s = 【?】
Form1.Print s;
Next i
End Sub
(答案) Static I sum(i)

'-------------------------------------------------------
'功能：窗体上建立了一个文本框Text1("输入口令")和一个命令按钮Command1("检查")。
' 判断密码是否正确，并显示相应提示
' 在加载窗体时设置密码框最大长度为8，密码显示字符为“*”
'-------------------------------------------------------
dim x as string
Private Sub Command1_Click()
x = Text1.Text
'**********SPACE**********
If x 【?】 "12345678" Then
MsgBox ("欢迎你用机!")
Else
MsgBox ("对不起，口令错")
End If
Text1.Text = ""
Text1.SetFocus
End Sub
Private Sub Form_Load()
Text1.Text = ""
'**********SPACE**********
Text1.【?】 = 8
'**********SPACE**********
Text1.【?】 = "*"
End Sub
(答案) = MaxLength PasswordChar

'-------------------------------------------------------
'功能：在窗体上画一个标签（名称为 Label1 ）和一个计时器（名称为 Timer1 ），
然后编写如下几个事件过程：要求：每一秒钟Label1更新显示一次系统时间
'-------------------------------------------------------
Private Sub Form_Load()
Timer1.Enabled = False
'**********SPACE**********
Timer1.Interval = 【?】
End Sub
Private Sub Form_Click()
'**********SPACE**********
Timer1.Enabled = 【?】
End Sub
Private Sub Timer1_Timer()
'**********SPACE**********
Label1.Caption = 【?】
End Sub
(答案) 1000 True Now 或 Time

'-------------------------------------------------------
'功能：写出程序运行后，单击窗体，Form1上显示的内容
' sum 函数的功能为累加求和
' isum = 1
' isum = 3
' isum = 6
' isum = 10
' isum = 15
'-------------------------------------------------------
Private Sub Form_Click()
Dim I As Integer, isum As Integer
'**********SPACE**********
For I = 1 To 【?】
isum = sum(I)
'**********SPACE*******
Form1.Print "isum ＝" 【?】
Next I
End Sub

Private Function sum(n As Integer)
Static j As Integer
'**********SPACE**********
【?】 j + n
sum = j
End Function
(答案) 5 & isum j =

三.级数
'--------------------------------------------------
'功能：以下程序段用于求∑n!
'-------------------------------------------------------
Private Sub Form_Click()
Dim sum As Integer, n As Integer
n = InputBox("请输入一个正整数")
sum = 0
For i = 1 To n
'**********SPACE**********
sum =【?】
Next i
Print sum
End Sub
Private Function mul(ByVal x As Integer)
Dim s As Integer, i As Integer
s = 1
'**********SPACE**********
For i = 1 To 【?】
s = s * i
Next i
'**********SPACE**********
【?】
End Function
(答案) sum + mul(i) x mul = s

'--------------------------------------------
'功能：由输入对话框输入n（n必须为大于零且小于30的自然数），
计算下列表达式的值，并在标签框Label1上显示。
sum=1/2+1/6+ ... +1/(k*(k+1)) (k<=n)
'-------------------------------------------------------
Private Sub Form_Click()
Dim n As Integer, sum As Double, k As Integer
n = Val(InputBox("n=", "请输入自然数n(n>0 且n<30)"))
'**********SPACE**********
Do While n <= 0 【?】 n >= 30
n = Val(InputBox("n=", "请重输入"))
Loop
sum = 0
k = 0
Do
'**********SPACE**********
k =【?】
sum = sum + 1 / (k * (k + 1))
'**********SPACE**********
Loop Until 【?】
Label1.Caption = "Sum=" + Str(sum)
End Sub
(答案) Or k + 1 k >= n

四.数字关系
'-------------------------------------------------------
'功能：过程suixian可以判断某一个数字是否是水仙花数，利用该过程找出三位数中所有水仙花数。
' 所谓"水仙花数"是指一个3位数，其各位数字立方和等于该数本身。
'-------------------------------------------------------
Private Sub Form_Click()
Dim i As Integer
For i = 100 To 999
'**********SPACE**********
【?】
Next i
End Sub
Public Sub suixian(x As Integer)
Dim i%, j%, k%
'**********SPACE**********
i =【?】
j = (x - i * 100) \ 10
k = x - i * 100 - j * 10
'**********SPACE**********
If 【?】 Then Print x
End Sub
(答案) call suixian (i) x \ 100 x = i ^ 3 + j ^ 3 + k ^ 3

五.数组
'-------------------------------------------------------
'功能：下面的程序段，用于实现在一个nXm的矩阵中，找出
值最大的元素所在的行和列，并输出其值及行号和列号。
'-------------------------------------------------------
Private Sub Form_Click()
Dim mat() As Integer
Dim n as integer, m As Integer
n = Val(InputBox("请输入矩阵的行数"))
m = Val(InputBox("请输入矩阵的列数"))
'**********SPACE**********
【?】
For i = 1 To n
For j = 1 To m
mat(i, j) = InputBox("请输入数组元素值")
mat(i, j) = Val(mat(i, j))
Next j
Next i
Print "所建立的矩阵为"
For i = 1 To n
For j = 1 To m
Print mat(i, j);
Next j
Print
Next i
Max = mat(1, 1)
For i = 1 To n
For j = 1 To m
'**********SPACE**********
If 【?】 Then
Max = mat(i, j)
col = j
'**********SPACE**********
【?】
End If
Next j
Next i
Print
Print "矩阵最大的元素的值为："; mat(row, col)
Print "它所在的行号为："; row; "列号为："; col
End Sub
(答案) ReDim mat(n, m) As Integer mat(i, j) > Max row = I

'-------------------------------------------------------
'功能：本程序利用二分法查找某数字n是否在已排序的数列当中，
' 若在其中则输出其在数列中的位置，否则输出-1。
'-------------------------------
Option Base 1
Sub birsearch(a(), ByVal low%, ByVal high%, ByVal key, index%)
Dim mid As Integer
mid = (low + high) \ 2
If a(mid) = key Then
'**********SPACE**********
【?】
Exit Sub
ElseIf low > high Then
index = -1
Exit Sub
End If
If key < a(mid) Then
'**********SPACE**********
high = 【?】
Else
low = mid + 1
End If
'**********SPACE**********
Call birsearch(a(), low, high, 【?】, index)
End Sub

Private Sub Command1_Click()
Dim b() As Variant, index As Integer
b = Array(5, 13, 19, 21, 37, 56, 64, 75, 80, 88, 92)
n = Val(Text1)
Call birsearch(b, LBound(b), UBound(b), n, index)
Print index
End Sub
(答案) index = mid mid – 1 key

'-------------------------------------------------------
'功能：单击“插入数据”按钮后，输入一个整型数据，
' 该数据会被插入到一个有序的数组a(1 to 10)中,插入该数据后数组还是有序的。
'-------------------------------------------------------
Option Base 1
Private Sub Command1_Click()
Dim a%(1 To 10), i%, k%, m%
Print "原数列是";
For i = 1 To 9
a(i) = (i - 1) * 3 + 1
Print a(i);
Next i
Print
m = Val(InputBox("输入要插入的数据"))
For k = 1 To 9
'**********SPACE**********
If (m < a(k)) Then 【?】
Next k
For i = 9 To k Step -1
'**********SPACE**********
a(【?】) = a(i)
Next i
'**********SPACE**********
a(k) = 【?】
Print "插入"; m; "后的数列是："
For i = 1 To 10
Print a(i);
Next i
Print
End Sub
(答案) Exit For i+1 m

'-------------------------------------------------------
'功能：写出程序运行时单击窗体后，Form1上的输出结果
' x(1) = 8
' x(2) = 6
' x(3) = 4
' x(4) = 3
' x(5) = 1
'-------------------------------------------------------
Private Sub Form_Click()
Dim x(5) As Integer
'**********SPACE**********
Dim i, j, t,【?】 As Integer
x(1) = 8
x(2) = 3
x(3) = 1
x(4) = 6
x(5) = 4
For i = 1 To 4
For j = i + 1 To 5
'**********SPACE**********
If x(i) 【?】 x(j) Then t = x(i): x(i) = x(j): x(j) = t
Next j, i
'**********SPACE**********
For k = 1 To 【?】
Form1.Print "x("; k; ")="; x(k)
Next k
End Sub
(答案) K < 5

'-------------------------------------------------------
'功能：以下程序段用于输出杨辉三角：结果样式如图1
'------------
Private Sub Form_Click()
Const n = 10
Dim arr(n, n) As Integer
For I = 1 To n
arr(I, I) = 1
'**********SPACE**********
【?】
Next I
For I = 3 To n
For j = 2 To I - 1
'**********SPACE**********
arr(i, j) =【?】
Next j
Next I
For I = 1 To n
For j = 1 To I
'**********SPACE**********
? 【?】& " ";
Next j
Print
Next I
End Sub
(答案) arr(i, 1) = 1 arr(i - 1, j - 1) + arr(i - 1, j) arr(i, j)

六.文件
'-------------------------------------------------------
'功能：本程序执行后，最终在窗体上打印数字7。
'----------------------
Private Sub Command1_Click()
Dim a As String
'**********SPACE**********
Open App.Path & "\abc.bat" For 【?】 As #1
n = 8
For I = 1 To n
Print #1, I + 1
Next I
Close #1
'**********SPACE**********
Open App.Path & "\abc.bat" For 【?】 As #1
For I = 1 To n
Input #1, a
If I Mod 5 = 0 Then
'**********SPACE**********
Print CInt(a) + 【?】
End If
Next I
Close #1
End Sub
(答案) Output Input 1

'--------------------------------------------------
'功能：本程序求3~100之间的所有素数（质数）并统计个数；
' 同时将这些素数从小到大依次写入顺序文件 dataout.txt；
' 素数的个数显示在窗体Form1上。
'-------------------------------------------------------
Private Sub Command1_Click()
Dim count As Integer, flag As Boolean
Dim t1 As Integer, t2 As Integer
'**********SPACE*****
Open App.Path & "\dataout.txt" For Output As 【?】
count = 0
For t1 = 3 To 100
'**********SPACE**********
flag = 【?】
For t2 = 2 To Int(Sqr(t1))
If t1 Mod t2 = 0 Then flag = False
Next t2
If flag Then
'**********SPACE*
count = 【?】
Write #1, t1
End If
Next t1
Form1.Print "素数个数"; count
Close #1
End Sub
(答案) #1 True count + 1

'-------------------------------------------------------
'功能：窗体中有两个List列表，及4个按钮。程序功能，单击
“产生随机数”按钮，随机产生20个随机数填入List1中
' “保存”按钮 作用是将数组内容写到文件中
' “读出”按钮 作用是将文件内容读到数组中
' “结束”按钮 作用是结束程序
'-------------------------------------------------------
Dim d(1 To 20) As Integer
Private Sub Command1_Click() '"产生随机数"
Dim i As Integer
List1.Clear
For i = 1 To 20
'**********SPACE**********
d(i) = Int(1 + 99 *【?】)
List1.AddItem d(i)
Next i
End Sub
Private Sub Command2_Click() '"保存"
Dim i As Integer
Open App.Path & "\MyFile3.txt" For Output As #1
For i = 1 To 20
'**********SPACE**********
Write 【?】, d(i)
Next i
Close #1
End Sub
Private Sub Command3_Click() '"读出"
Dim x As String
Open App.Path & "\MyFile3.txt" For Input As #1
List2.Clear
'**********SPACE**********
Do While Not 【?】
Input #1, x
List2.AddItem x
Loop
Close #1
End Sub
Private Sub Command4_Click() '"结束"
End
End Sub
(答案) Rnd #1 EOF(1)

'-------------------------------------------------------
'功能： 本程序实现功能：将顺序文本文件 “MYFILE.TXT” 的
' 内容一个字符一个字符地读入文本框txtTest中
'-------------------------------------------------------
Private Sub Form_Click()
Dim InputData As String * 1
txtTest.Text = ""
'**********SPACE**********
Open App.Path & "\MYFILE.TXT" For 【?】 As #1
'**********SPACE**********
Do While 【?】 EOF(1) ' Do While Not 【?】
Input #1, InputData
'**********SPACE**********
txtTest.Text = txtTest.Text + 【?】
Loop
Close #1
End Sub
(答案) Input Not InputData

七.杂项
'-------------------------------------------------------
'功能：程序输出结果为：n=3 x=42 y=9
'------------------
Private Sub Command1_Click()
Dim n, x, y As Integer
'**********SPACE**********
n = 0: x =【?】: y = 0
Do While x < 20
'**********SPACE**********
n = n 【?】
y = x + y
x = x * (x + 1)
'**********SPACE**********

Form1.Print "n=" & Str(n)
Form1.Print "x=" & Str(x)
Form1.Print "y=" & Str(y)
End Sub
(答案) 1 + 1 Loop

'-------------------------------------------------------
'功能：利用下面的过程求m!和m*n
'-------------------------------------------------------
Private Sub Form_Click()
Dim m As Integer, n As Integer
m = 2
n = 3
'**********SPACE**********
【?】
End Sub
Private Sub find(x As Integer, y As Integer)
Dim s, i As Integer
'**********SPACE**********
【?】
For i = 1 To x
s = s * i
'**********SPACE**********
p=【?】
Next i
Print s, p
End Sub
(答案3) call find(m,n) s = 1 p + y

'-------------------------------------------------------
'功能：以下程序段用于实现矩阵转置，即将一个n×m的矩阵的行和列互换
'-------------------------------------------------------
Private Sub Form_Click()
Const n = 3
Const m = 4
Dim a(n, m), b(m, m) As Integer
For I = 1 To n
For j = 1 To m
a(I, j) = Int(Rnd * 90) + 10
Next j
'**********SPACE**********
【?】
For I = 1 To n
For j = 1 To m
'**********SPACE**********
【?】
Next j
Next I
Print "矩阵转置前"
For I = 1 To n
For j = 1 To m
Print a(I, j);
Next j
'**********SPACE**********
【?】
Next I
Print "矩阵转置后"
For I = 1 To m
For j = 1 To n
Print b(I, j);
Next j
Print
Next I
End Sub
(答案) Next I b(j, i) = a(i, j) Print

'功能：下面的程序段用于打印出以下图形
'
' *
' ***
' *****
' *******
'