The following script will compute factorials using java. Just copy and paste the below script into your preferred IDE (Integrated Development Environment) and run it.
/*
Programmer: Jarrod
Date: June 25, 2018
Filename: FactorialApp.java
Purpose: To calculate factorial for user input 1 through 9 (or 16
for enhancement non-long... or 40 for enhancement with long).
*/
//packages to import
import java.util.Scanner;
import java.text.NumberFormat;
public class FactorialApp
{
public static void main(String args[])
{
//welcome the user
System.out.println("Welcome to the Factorial Calculator");
System.out.println(); //print a blank line
//construct Scanner object
Scanner sc = new Scanner(System.in);
//set up do-while, perform calculations, and display output
String choice = "n";
do
{
//get input from the user
System.out.print("Enter an integer value greater than 0 and less than 10: ");
int n = sc.nextInt();
long factorial = 1L;
//use a for loop to calculate the future value
for(int i = 1; i <= n; i++)
{
factorial = factorial * i;
} //end for loop
//construct formatting object and display results
System.out.println("\nThe factorial of " + n + " is " + factorial);
//see if the user wants to continue
System.out.print("\nContinue? (y/n): ");
choice = sc.next();
System.out.println();
} while(choice.equalsIgnoreCase("y"));//continue program based on input y or Y
} //end main()
} //end class