This code returns the factorial of a number
To use that, you should require the file, see below:
require_relative "factorial"
Now you can use number.flong or number.fshort
.flong return a string value:
5.flong => "5 x 4 x 3 x 2 x 1 = 120"
.fshort return a integer value, only the result of the factorial:
5.fshort => 120