Question

Factorials in Java: Write out your Program Design for how to automate the testing. The objective is to repeat the factorial calculation for different values of n, as n changes from 2, 3, 4, 5, 6, 7..

1) test for an int

2) test for a long

3)test for a double

Answer 1

Code:

import java.util.*;
class sample
{
   public static void main(String args[])               //main method
   {
       Scanner scan=new Scanner(System.in);           //object creation for scanner
       int n=scan.nextInt();                   //taking input n from user to what extent i've to perform factorial
       long fact=1;                      
       System.out.println("Integers");
       for(int i=2;i<=n;i++)                   //iterating loop from 2 to n integers
       {
           fact=fact*i;                   //finding factorial
           System.out.println(i+"    "+fact);       //printing factorial
       }
       long fact1=1;
       System.out.println("Long integer");
       for(long i=2;i<=n;i++)                   //iterating loop from 2 to n long integers
       {
           fact1=fact1*i;                   //finding factorial
           System.out.println(i+"    "+fact1);       //printing factorial
       }
       double fact2=1;
       System.out.println("Double");
       for(double i=2;i<=n;i++)               //iterating loop from 2 to n doubles
       {
           fact2=fact2*i;                   //finding factorial
           System.out.println(i+"    "+fact2);       //printing factorial
       }
   }
}