发布时间 : 星期二 文章vb第四章选择结构和循环结构编程题更新完毕开始阅读b72c1dffd1d233d4b14e852458fb770bf68a3b61
For z = 1 To 50 w = 40 - x - y - z
If 10 * x + 5 * y + 2 * z + w = 100 And x * y * z * w > 0 Then h = Format(x, \& Format(z, \List1.AddItem h End If Next z Next y Next x End Sub
10.找出三位数的回文数并打印，并求其个数
Private Sub Command1_Click() Dim n As Integer
For n = 101 To 999 a = Int(n / 100)
b = Int((n - a * 100) / 10) c = n - a * 100 - b * 10
If a = c Then List1.AddItem n Next
Print List1.ListCount End Sub
10-2回文字判断
1）按定义判断
先求出字符串的反序字符串，然后和原字符串比较，如果相等则是回文，否则不是回文。
Dim str As String, i As Integer
'以下求Text1中文本的反序串str For i=1 To Len(Text1)
str=Mid(Text1, i, 1) & str Next i
If str=Text1 Then MsgBox \是回文\不是回文\（2）首尾字符的成对比较 将字符串折半比较，若每对字符都相等则是回文，否则只要有一对字符不等就不是回文。
Dim i As Integer
For i=1 To Len(Text1) \\ 2
If Mid(Text1, i, 1) <> Mid(Text1, Len(Text1) - i + 1, 1) Then Exit For Next i
If i > Len(Text1) \\ 2 Then MsgBox \是回文\不是回文\
11.求1-10之间阶乘题
Private Sub Command1_Click() Dim i As Integer, s As Double i = 1
Do While i <= 10 s = 1
For j = 1 To i s = s * j Next j
Print i; \ i = i + 1 Loop End Sub
12.水仙花题
Private Sub Command1_Click() Dim i As Integer, m As Integer For i = 100 To 999 m = (i Mod 10) ^ 3 + _
(i \\ 10 Mod 10) ^ 3 + (i \\ 100) ^ 3 If m = i Then Print i Next i End Sub
Private Sub Command2_Click()
For a = 1 To 9: For b = 0 To 9: For c = 0 To 9 x = a * 100 + b * 10 + c
If x = a ^ 3 + b ^ 3 + c ^ 3 Then Print x End If Next Next Next End Sub
13.打印菱形
Private Sub Command1_Click() For i = 1 To 5
Print Spc(6 - i); For j = 1 To i
Print Spc(1); \ Next j
Print Next i
For i = 5 To 1 Step -1 Print Spc(6 - i); For j = 1 To i
Print Spc(1); \ Next j Print Next i End Sub
14.用Do循环设计例4.11中的s=1×2×3×…×n的值，其中n由
输入对话框获得。
Private Sub Command1_Click()
n = InputBox(\请输入n的值：\输入\ s = 1 i = 1 Do
If i > Val(n) Then Exit Do s = s * i i = i + 1 Loop
MsgBox \计算结果\End Sub
15. 求由数字0、1、2、3、4组成的所有无重复数字的3位正整数。
Private Sub Command1_Click()
Dim a As Integer, b As Integer, c As Integer, n As Integer For a=1 To 4
For b=0 To 4 For c=0 To 4
If a <> b And b <> c And a <> c Then
Print a * 100 + b * 10 + c;或为 List1.AddItem a * 100 + b * 10 + c
n=n + 1
If n Mod 5=0 Then Print End If Next c Next b Next a End Sub
课后题 1.
Private Sub Command1_Click()
x = Val(InputBox(\请输入一个数\显示\If x > 0 Then x = MsgBox(\是正数\显示) If x = 0 Then x = MsgBox(\是零\显示) If x < 0 Then x = MsgBox(\是负数\显示) End Sub
2.
Private Sub Command1_Click() Dim a As Single Dim b As Single Dim c As Single Dim t As Single
a = Val(InputBox(\请输入第一个数\从大到小排序\b = Val(InputBox(\请输入第二个数\从大到小排序\c = Val(InputBox(\请输入第三个数\从大到小排序\If a < b Then t = a: a = b: b = t If a < c Then t = a: a = c: c = t If b < c Then t = b: b = c: c = t
Print \从大到小的顺序为：\End Sub
3.
Private Sub Command1_Click() Static n As Integer x = Text1.Text If x = \
Label1.Caption = \欢迎进入本系统\Else
Label1.Caption = \输入错误\ n = n + 1
If n = 3 Then End End If End Sub
Private Sub Command2_Click() Text1.Text = \End Sub