Private sub Commnnd1_CLick()
   Dim i As Integer
   Dim s As Long
   For i = 1 to 5
     s = s + t(i)
   Next i
   print "s";s
End sub
Function t(i As Inteher) AS Long
   If i = 0 Then
      t = 1
   else
      t = 1 * t(i-1)
   End if

s 5

这个是不是递归调用，每次都调用t(i)，直到i=0 ，即t =1 。跳出调用，进行求和计算