计算机VB考试复习.doc

1、两个时间函数now（）、today（）、timeofday（）2、级数求和编写程序，计算并输出下列数列前35项的和。 (1-2-3),(4-5-6),(7-8-9), ,(3n+1)-(3n+2)-(3n+3), (注意，n=0,1,2,3)Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim i, s As Integer s = 0 For i = 0 To 34 s += (3 * i + 1) - (3 * i + 2) - (3 * i + 3) Next MsgBox(s) End Sub 编写程序计算并输出下面数列前n项的和，当第一次出现和数的绝对值大于5000时求和终止。 1*2*3,-2*3*4,3*4*5,-4*5*6,(-1)(n-1)*n*(n+1)*(n+2),（其中， 表示幂运算） Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click Dim i, t, s As Integer i = 1 Do t = (-1) (i - 1) * i * (i + 1) * (i + 2) s += t i += 1 Loop Until Math.Abs(s) 5000 MsgBox(s) End Sub图形题1、用循环编写程序，单击“生成图形”按钮，在多行文本框中输出如图所示的三角形，界面如下：设计如图所示的生成数组界面，点击“生成数组”按钮，完成如下功能：由程序随机产生一个66的二维数组，显示在textbox1文本框中，并在textbox2文本框中输出数组中的最大元素。有一个数列，前三项都是1，从第四项开始，每一项都是其相邻前三项之和的1/2。试编写函数过程，求数列第n项的值。要求调用该过程，计算并输出n=30时前n项的和。(保留3位小数）Function f(ByVal n As Integer) As Double Dim f1, f2, f3, fn As Double f1 = 1 f2 = 1 f3 = 1 For n = 4 To n fn = (f1 + f2 + f3) / 2 f1 = f2 f2 = f3 f3 = fn Next f = fnEnd Function Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim n As Integer Dim s As Double For n = 1 To 30 s = s + f(n) Next MsgBox(Format(s, 0.000) End Sub编写判断一个正整数是否为“完数”的函数过程。在事件过程中调用该过程，计算区间200，500上“完数”的个数。完数的含义是：该数的所有因子之和等于该数。例6=1+2+3。结果： 1Function ws(ByVal n As Integer) As Boolean Dim i, s As Integer s = 0 For i = 1 To n - 1 If n Mod i = 0 Then s = s + i End If Next If s = n Then ws = True Else ws = False End If End FunctionPrivate Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim n, i As Integer For i = 200 To 500 If ws(i) Then n = n + 1 End If Next MsgBox(Str(n)End Sub已知数据文件dat5.dat中已存储有20个学生一门课程的成绩（整型），编程将该文件中20个学生的成绩赋给整型数组score，然后按照从高分到低分对成绩排序，并按一行五个输出显示。Dim score(19), i, j, t As Integer FileOpen(1, d:10文件da5.dat, OpenMode.Input) For i = 0 To 19 Input(1, score(i) Next For i = 0 To 18 For j = i + 1 To 19 If score(i) score(j) Then t = score(i) score(i) = score(j) score(j) = t End If Next Next Dim str1 A