例:编写一个函数过程,求n!的值 Public Function fac(n As Integer)As Integer k=1 a Form1 For i=1 To n 输入:6 输出:873 算 Next i fac=k End functionPublic Function fac(n As Integer) As Integer k = 1 For i = 1 To n k = k * i Next i fac = k End Function 例：编写一个函数过程，求n！的值