2012年计算机考试二级VB考点及习题(4)
例如:1、if 语句: Private Sub Form_Click() Dim x As Integer, y As Integer Dim z As Single x = 0.2 y = 1 If (x >= 1) Then z = Log(x) ElseIf x >= 0 And x < 1 And y >= 0 Then z = 2 * x - y Else z = Exp(x + y) End If Print "z=" + Str(z) End Sub 结果: z=-1 2、Select Case语句 Private Sub Form_Click() Dim ch As String, i As Integer ch = "c" Select Case ch Case "A", "a" i = 1 Case "B", "b" i = 2 Case "C", "c" i = 3 Case "D", "d" i = 4 Case Else i = 5 End Select Print "运行结果" + Ucase(ch) + Str(i) End Sub 结果:运行结果C3 ② 循环结构 1、For------Next (循环次数的计算) 特例: 例如:有循环:for I=n1 to n2 step n3 下列哪些语句会影响循环次数( ) A. n1=n1+I B. n3=2*n3 C. n2=n2+n3 D. I=I+n3 2、Do------Loop (While,Until) 例如:运行下面的程序,单击窗体后在窗体上的内容是( );若将程序中的A语句与B语句的位置互换,再次执行程序,单击窗体后在窗体上显示的内容是( ) Private Sub Form_Click() Dim a As Integer, b As Integer a = 0: b = 0 Do While a <= 8 a = a + 2 ’A语句 b = b + a * a ’B语句 Loop Print a, b End Sub 例如:窗体上显示的结果: Private Sub Form_Click() Dim p As Integer, i As Integer, n As Integer p = 2: n = 20 For i = 1 To n Step p p = p + 2 n = n - 3 i = i + 1 If p >= 10 Then Exit For Next i Print i, p, n End Sub 一、 InputBox函数 MsgBox函数 (注意参数含义及顺序) x=InputBox(_____,______,_______) 写出显示下图信息框的MsgBox函数 相关资料 |