1

方法1:
for I = 1到100
if I mod 2 = 0 then
s = s-1/I
else
s = s+1/I
end if[/br

方法2:
k = 0
for a = 1 to 99 step 2
s = 1/a-1/(a+1)
k = k+s
next a
msgbox

方法3:
for I = 1 to 100
s = s+(-1)(I+1)*(1/I)
next I
text 1 . text = s

方法四:
private subform _ load()
s = 0
for I = 1 to 100
s = s+1/I
next I
for a = 2 to 100 step 2[

MsgBox (c)
End Sub

方法五:
a = 1
s = 0
for I = 1 to 100
a =(-1)(I+1)/I
s = s+a
。

方法六:
s = 0
for I = 1 to 100
s = s+(1/I)*(-1)((I+1)mod 2)
next I