Factorial.scala

object Factorial {
    def fact(n: Int): Int = if(n == 0) 1 else n * fact(n - 1)
    def main(args: Array[String]) = {
        val n = if(args.length == 0) 1 else Integer.parseInt(args(0))
        1 to n foreach {i => println(i + "! = " + fact(i))} 
    }
}