vb第二版習(xí)題冊(cè) 部分答案

1、Option Explicit 6-1 Dim i As Integer Dim x As Integer Private Sub CmdExit_Click( End End Sub Private Sub CmdJudge_Click( x = Val(txtInput.Text For i = 2 To x / 2 If x Mod i = 0 Then Exit For Next If x Mod i <> 0 Then MsgBox Str(x & "是素?cái)?shù)！" Else MsgBox Str(x & "不是素?cái)?shù)！"

2、 End If End Sub 6-3 Option Explicit Private Sub CmdCalculate_Click( Dim x As Integer, n As Integer Dim s As Single, t As Single s = 1 x = Val(txtX.Text n = 1 Do n = n + 1 t = n * x / x n s = s + t If t < 10 -5 Then Exit Do Loop txtS = Str(s End Sub Private Sub CmdExit_Click( End End Sub 6-3改 Opti

3、on Explicit Private Sub CmdCalculate_Click( Dim x As Integer, n As Integer Dim s As Single, t As Single s = 1 x = Val(txtX.Text n = 1 Do n = n + 1 t = (n * x / x n * (-1 (n - 1 s = s + t If Abs(t < 10 -5 Then Exit Do Loop txtS = Str(s txtS = Format(txtS, "0.000000000" '0到1之間的小數(shù)，例如0.

4、5，運(yùn)行時(shí)小數(shù)點(diǎn)前的0本不能顯示，用Format函數(shù)后能了 End Sub Private Sub CmdExit_Click( End End Sub 6-4 Dim n As Integer Private Sub CmdClear_Click( txtS.Text = "" txtV.Text = "" txtL.Text = "" txtS.SetFocus End Sub Private Sub CmdExit_Click( Unload Me End Sub Private Sub CmdInvert_Click( Dim

5、 i As Integer Dim s As String n = Len(txtS.Text For i = n To 1 Step -1 s = s + Mid(txtS.Text, i, 1 Next i txtV.Text = s End Sub Private Sub CmdLen_Click( n = Len(txtS.Text txtL.Text = n End Sub 7-10 Option Explicit Dim A(20 As Integer Private Sub CmdClear_Click( Text1 = "" List2.Clear End

6、Sub Private Sub CmdExit_Click( Unload Me End Sub Private Sub CmdForm_Click( Dim i As Integer, s As String For i = 1 To 20 A(i = Int(21 * Rnd + 20 s = s & A(i & " " If i = 10 Then s = s & Chr(13 & Chr(10 End If Next i Text1 = s End Sub Private Sub CmdTong_Click( Dim t As Int

7、eger Dim B(20 To 40 As Integer, i As Integer For i = 1 To 20 B(A(i = B(A(i + 1 Next i For i = 20 To 40 If B(i <> 0 Then List2.AddItem i & "出現(xiàn):" & B(i & "次" Next i End Sub 8-1 Option Explicit Dim sPhrase As String, sEncrypted As String Dim iLen As Integer Private

8、 Sub CmdOperate_Click(Index As Integer Dim sCurrent As String, sNew As String Dim sDecrypted As String Dim x As Integer If Index = 0 Then sPhrase = InputBox("請(qǐng)輸入短語(yǔ)", "短語(yǔ)將被加密" iLen = Len(sPhrase ElseIf Index = 1 Then sEncrypted = "" For x = 1 To iLen sCurrent = Mid(sPhra

9、se, x, 1 sNew = Chr(Asc(sCurrent + 2 sEncrypted = sEncrypted & sNew Next x MsgBox sEncrypted, vbExclamation, "加密的短語(yǔ)" ElseIf Index = 2 Then For x = 1 To iLen sCurrent = Mid(sEncrypted, x, 1 sNew = Chr(Asc(sCurrent - 2 sDecrypted = sDecrypted & sNew Next x MsgBox sDecrypted, vbExclam

10、ation, "解密的短語(yǔ)" Else Unload Me End If End Sub 9-4 Option Explicit Private Sub CmdClear_Click( Text1.Text = "" Text2.Text = "" Text3.Text = "" End Sub Private Sub CmdExit_Click( Unload Me End Sub Private Sub Option1_Click(Index As Integer Dim a As Integer, b As

11、Integer Dim m As Integer, d As Integer a = Text1 b = Text2 m = common(a, b If Index = 0 Then Text3 = m Else d = a * b / m Text3 = d End If End Sub Private Function common(ByVal a As Integer, ByVal b As Integer As Integer Dim r As Integer Do r = b Mod a If r = 0 Then Exit Do b = a a = r Loop While r

12、<> 0 common = a End Function 9-6 Option Explicit Private Sub CmdSearch_Click( Dim i As Integer For i = 3 To 100 Step 2 If prime(i And prime(i + 2 Then Print Str(i & "," & Str(i + 2 End If Next i End Sub Private Function prime(n As Integer As Boolean Dim i As Integer For i = 2

13、 To n - 1 If n Mod i = 0 Then prime = False Exit Function End If Next i prime = True End Function 9-7 Option Explicit Private Sub CmdClear_Click( Text1.Text = "" Text2.Text = "" Text3.Text = "" End Sub Private Sub CmdExit_Click( End End Sub Private Sub CmdTran_Click( Di

14、m s As Long Dim bin( As String Dim i As Integer, k As Integer For i = 1 To Len(Text2 k = k + 1 ReDim Preserve bin(k bin(k = Mid(Text2, i, 1 Next i Call tran(bin, s Text3 = s End Sub Private Sub Text1_Change( Dim n As Integer n = Val(Text1.Text Label3.Caption = Str$(n + "進(jìn)制數(shù)" End Sub Privat

15、e Sub tran(vary( As String, p As Long Dim i As Integer, n As Integer n = Val(Text1.Text For i = 1 To UBound(vary If Val(vary(i >= 0 And Val(vary(i <= 9 Then p = p + Val(vary(i * n (UBound(vary - i End If If Asc(UCase(vary(i >= 65 And Asc(UCase(Val(i <= 70 Then p = p + (Asc(UCase(vary(i -

16、 65 + 10 * n (UBound(vary - i End If Next i End Sub 10-4 Option Explicit Dim den As Integer, num As Integer Private Sub Command1_Click( lowterm num, den Text3.Text = CStr(den Text4.Text = CStr(num End Sub Private S ub Command2_Click( Text1.Text = "" Text2.Text = "" Text3.Text = &

17、quot;" Text4.Text = "" End Sub Private Sub Command3_Click( End End Sub Private Sub Text1_Change( den = Val(Text1.Text End Sub Private Sub Text2_Change( num = Val(Text2.Text End Sub Sub lowterm(x As Integer, y As Integer Dim gcdvalue As Integer gcdvalue = gcd(x, y If gcdvalue > 1 Th

18、en x = x / gcdvalue y = y / gcdvalue End If End Sub Private Function gcd(ByVal a1 As Integer, ByVal b1 As Integer Dim remainder As Integer remainder = a1 Mod b1 If remainder = 0 Then gcd = b1 Else a1 = b1 b1 = remainder gcd = gcd(a1, b1 End If End Function 10-8 Option Explicit Private Sub Command1_Click( Dim n As Integer, m As Integer For n = 10 To 9999 Call Armstrong(n Next n End Sub Private Sub Command2_Click