Question

单机窗体时，求-1+3-5+7-9.....+99的结果并输出 VB题

Answer 1

Private Sub form1_Click()
k = -1
s = 0
For i = 1 To 99 Step 2
s = s + k * i
k = k * (-1)
Next i
Print s
End Sub
单击窗体？那就是窗体事件

Answer 2

Private Sub Command1_Click()
For i = 1 To 99 Step 2
if i mod 4 = 1 then s = s + i else s = s - i
Next i
Print s
End Sub

Answer 3

Private Sub Command1_Click()
For i = 1 To 99 Step 2
t = ((i + 1) / 2) Mod 2
s = s + i * (-1) ^ t
Next i
Print s
End Sub

Answer 4

变量在使用前最好先定义，养成良好的习惯
dim i as integer,s as integer
for i = 1 to 49
s = s + (-1)^i*(2*i+1)
next i
printf s