Factorial Function

Exercise Solution

1. First, we create a function and define the input data as Integer and the output data as Long (as the number may increase considerably)

   Function FacTorial(N As Long) As Double
   

2. We declare the variables and assign the value 1 to the variable Result. Remember that zero factorial equals to one (0! = 1)

   Dim i As Double
   Dim Result As Double
   
   Result = 1
   

3. We create a For Next loop, whose final value (N!) comes from the input of the function, in which each iteration advance a step in the multiplication (accumulating the result in the variable Result).

   For i = 1 To N
       Result = Result * i
   Next i
   FacTorial = Result
   

Consolidated Answer

    Function FacTorial(N As Integer) As Double

    Dim i As Integer
    Dim Result As Double

    Result = 1

    For i = 1 To N
        Result = Result * i
    Next i

    FacTorial = Result

    End Function