Exercise
Function Factorial
Objetive
The factorial of a number is expressed as follows:
n! = n · (n-1) · (n-2) · (n-3) · ... · 3 · 2 · 1
For example,
6! = 6·5·4·3·2·1
Create a recursive function to calculate the factorial of the number specified as parameter:
Console.Write ( Factorial (6) );
would display 720
Code
Imports System
Public Class Exercise114
Public Shared Function Factorial(ByVal num As Integer) As Integer
If num = 0 Then
Return 1
Else
Return num * Factorial(num - 1)
End If
End Function
Public Shared Sub Main()
Console.WriteLine("Enter a number:")
Dim number As Integer = Convert.ToInt32(Console.ReadLine())
Console.WriteLine(Factorial(number))
Console.WriteLine(Factorial(6))
End Sub
End Class