一道vb题1！-2！···

Question

题目：（事件）单击窗体。
（响应）已知sum=1！-2！+3！-4！···-10！
将sum结果值输出到窗体上。
实用do while···loop语句完成程序
答对我会增加财富值的！！谢谢

Answer 1

Private Sub Form_Click()
Dim sum As Integer, a As Integer, fact As Integer
a = 1
sum = 1
fact=a
Do While a <10
a=a+1
fact=fact*a
sum=sum+(-1)^(a-1)*fact
Loop
Print "计算结果是：" ; sum
End Sub

Ps:这应该自己想一下的，这不算难，几句就可搞定来自：求助得到的回答

Answer 2

Private Sub Form_Click()
Dim j As Double, sum As Double, n As Integer, fh as integer
j = 1
n = 1
fh = 1 '控制符号，第一为1 ，n=2时为-1
Do While n <= 10
j = j * n
sum = sum + j * fh
fh = - fh
n = n + 1
Loop
Print sum
End Sub

Answer 3

Private Sub Form_Click()
Dim jc As Double, sum As Double, n As Integer
jc = 1
n = 1
Do While n <= 10
jc = jc * n
sum = sum + jc
n = n + 1
Loop
Print sum
End Sub

Answer 4

Private Sub Form_Click()
Dim j As Double, sum As Double, n As Integer, k as integer
j = 1
n = 1
k = 1
Do While n <= 10
j = j * n
sum = sum + j * k
k = - k
n = n + 1
Loop
Print sum
End Sub