Private Sub Form_Click() Dim intx As Integer intx = InputBox("请输入x的值:") Select Case intx Case Is < 0 MsgBox "函数无定义" Case Is < 20 MsgBox 25 * intx - 5 Case 20 To 50 MsgBox 50 Case Is < 100 MsgBox 5 * intx + 19 Case Else MsgBox 100 End Select End Sub@H_301_0@
@H_301_0@3.for 循环 @H_301_0@注意步长与初值和终值的关系 @H_301_0@可用exit for 跳出循环 @H_301_0@
s=0 For i=1 to 100 s=s+I If s>4000 then exit for Next I@H_301_0@
@H_301_0@4.while 循环 @H_301_0@例子:求1+2+···+100
Private Sub Form_Click() i = 0 s = 0 (do) While i <= 100 s = s + i i = i + 1 wend( Loop) Print s End Sub
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@H_301_0@5.Do 循环(可以用exit do 跳出循环) @H_301_0@ 1. Do while @H_301_0@ 循环体 @H_301_0@ Loop @H_301_0@注意:do while 循环与while循环完全相同,即首先判断条件,当条件成立时重复执行循环体。(例子如上) @H_301_0@ 2.do ···loop while @H_301_0@注意:此循环是先执行一次,再判断条件。当条件成立时,重复执行循环。 @H_301_0@ Do @H_301_0@ 循环体 @H_301_0@ Loop while 条件 @H_301_0@例子:Private Sub Form_Click() Dim i As Integer Dim s As Integer i = 0 s = 0 Do s = s + i i = i + 1 Loop While i <= 100 Print s End Sub@H_301_0@
@H_301_0@ 3.Do Until @H_301_0@ 注意:DO until与DO while结构类似,只是前者在条件不满足时成立,后者反之。 @H_301_0@例子:Private Sub Form_Click() Dim i As Integer Dim s As Integer Do Until i > 100 s = s + i i = i + 1 Loop Print s End Sub@H_301_0@
@H_301_0@ 4.DO ···loop until @H_301_0@注意:Do ···loop until 结构与Do until 类似,只是前者是先执行一次循环,再判断,在条件不成立时重复执行循环体。 @H_301_0@例子:Private Sub Form_Click() Dim i As Integer Dim s As Integer Do Until i > 100 s = s + i i = i + 1 Loop Print s End Sub
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@H_301_0@6.for each 循环 @H_301_0@注意:for each 循环与for循环类似,但是for each用于数组或对象集合中的每一个元素重复一组语句,在数组中的运用我们并不陌生。 @H_301_0@例子:Private Sub Form_Click() Dim a(100) As Integer For i = 1 To 100 a(i) = i s = s + a(i) Next i Print s End Sub