vb期末考试-填空题.docVIP

1 下面程序是接受用户从键盘上输入的一个正整数，找出大于或等于该数的第一个素数。 Option Explicit Private Sub Command1_Click() Dim n As Integer, k As Integer Dim i As Integer n = InputBox(请输入一个正整数) k=n Do For i = 2 To Sqr(k) If k Mod i = 0 Then Exit For Next i If i sqr(k) Then Exit Do Else k=k+1 End If Loop Print 大于等于; n; 的第一个素数是; k 2 以下程序的功能是随机产生20个1到100之间的正整数，去掉一个最大数和最小数，然后取其平均数。 Private Sub Form_Click() Dim s As Integer, i As Integer Dim k As Integer, max As Integer, min As Integer Randomize k = Int(Rnd * 100) + 1 max = k: min = k s=k For i = 1 To 19 k = Int(Rnd * 100) + 1 s = s + k If kmax Then max = k If k min Then min = k Next i s = s-max-min Print average=; s / 18 3 随机生成10个整数，并放入一个一维数组中，然后将其前5个元素与后5个元素对换，即：第1个元素与第10个元素互换，第2个元素与第9个元素互换……分别输出数组原来各元素的值和对换后各元素的值。 Private Sub Command1_Click() Dim a(10) As Integer Dim i As Integer, j As Integer Print 原序列： For i = 1 To 10 a(i) = Int(Rnd * 90) + 10 Print a(i); Next i Print For i = 1 To 5 t = a(i) a(i)=a(11-i) a(11-i)=t Next i Print 交换后的序列： For i = 1 To 10 Print a(i); Next i Print End Sub End Sub 4 以下程序的功能是随机生成20个100到200之间的正整数，输出其最大元素和其所在的位置，请按要求完善程序。 Private Sub Command1_Click() Dim a(20) As Integer, i As Integer Dim max As Integer, maxi As Integer Randomize For i = 1 To 20 a(i) = int(rnd*101)+100 Print a(i); Next i Print max=a(1) maxi = 1 For i = 2 To 20 If a(i) max Then max = a(i) maxi=i End If Next Print 最大元素为; max; 其所在的数组元素位置号为; maxi End Sub 5 在文本框Text1中输入一串字符，判别其是否是回文字符串。所谓回文字符串是指正读和反读都一样的字符串，比如ABBA、DEAED等就是回文字符串。 Private Sub Command1_Click() Dim s As String, n As Integer, m As Integer s = Text1.Text n = 1 m=Len(s) Do While n = m If Mid(s, n, 1) = Mid(s, m, 1) Then m = m - 1 n=n+1 Else