求n的階乘【VB代碼實現】

求

For語句實現

Private Sub Command1_Click()
    Dim s As Long, n As Integer, i As Integer
    n = Val(Text1.Text)
    s = 1
    For i = 1 To n
        s = s * i
    Next i
    Label4.Caption = Str(s)
End Sub

Do While語句實現

Private Sub Command1_Click()
    Dim s As Long, n As Integer, i As Integer
    n = Val(Text1.Text)
    s = 1
    i = 1
    Do While i <= n
        s = s * i
        i = i + 1
    Loop
    Label4.Caption = Str(s)
End Sub

學習要求：

1、讀懂題意，根據每一項的變化寫出通項公式。

2、設定相應的變量來解決問題，理解各變量的作用。