Question

求助 vb中 单击计算按钮出现1！+2！+3！....+20！的值 哪出错了

Private Sub Command1_Click()
Dim S As Double
Dim Sum As Double
Dim I As Integer, J As Integer
Sum = 0
For I = 1 To 20
'**********found************* '请不要删除该行'
S = 1
'**********found************* '请不要删除该行'
For J = 1 To 20
S = S * J
Next J
Sum = Sum + S
Next I
Text1.Text = Str(Sum)
End Sub
Private Sub Command2_Click()
End
End Sub
Private Sub Form_Load()
Text1.Text = ""
End Sub

Answer 1

For J = 1 To 20 这句错误，应改成For J = 1 To I ，否则每次I循环求得的S均为20!/I!而不是I!

Answer 2

Private Sub Command1_Click()
Dim S As Double
Dim Sum As Double
Dim I As Integer, J As Integer
Sum = 0
For I = 1 To 20
'**********found************* '请不要删除该行'
S = 1
'**********found************* '请不要删除该行'
For J = 1 To 20--------------------------------------------这里，内循环是算1-20的阶乘，所以循环终值要改变，应为 for j=1 to i
------------------------------------------------------------------------------------------
S = S * J
Next J
Sum = Sum + S
Next I
Text1.Text = Str(Sum)
End Sub
Private Sub Command2_Click()
End
End Sub
Private Sub Form_Load()
Text1.Text = ""
End Sub