7.5 vb求和

来源：百度知道 编辑：UC知道 时间：2024/05/21 11:38:31
5.输入n，求表达式：1+(1+2)+(1+2+3)+...+(1+2+...+ n)之和 。 在文本框text1中输入n，在文本框text2中输出求和结果，点击命令按钮Command1运行。

Option Explicit
Private Sub Command1_Click()
Dim n As Long, sum As Long, i As Long
n = Text1.Text
For i = 1 To n
sum = sum + i * (i + 1) \ 2
Next i
Text2.Text = sum
End Sub

Private Sub Command1_Click()
Dim i As Integer
dim j as integer
Dim n As Integer
Dim sum As Long
Dim sum2 As Long
n = Val(Text1.Text)
If n > 0 Then
For i = 1 To n
For j = 1 To i
sum2 = sum2 + j
Next j
sum = sum + sum2
Next i
Text2.Text = CStr(sum)
End If
End Sub