Question

Programming JAVA to provide an iterative and recursive solution ( tow separate methods) for calculating the factiorial of a number. The factorial of a number is denoted by, for example 5! = 5 * 4 * 2 * 1.

Answer 1

Factorial.java

//This package is imported to use scanner class
import java.util.*;
public class Factorial
{
//Method to find factorial of number using iteration. Here for loop is used for iteration.
int factorial1(int n1)
{
int fact=1;
for(int i=1;i<=n1;i++)
{
fact=fact*i;
}
return fact;
}
//Method to find factorial of number using recursion.
int factorial2(int n2)
{
if(n2==0)
return 1;
else
return (n2*factorial2(n2-1));//recursively calling
}
public static void main(String args[])
{
//scanner class object is first created to take inputs from users.
Scanner sc=new Scanner(System.in);
Factorial f1=new Factorial();
System.out.println("Enter a number to find factorial of the number using iteration:");
//Reading input from user using scanner class object
int n1=sc.nextInt();
int fact1=f1.factorial1(n1);
System.out.println("The factorial of the number calculated using iteration is:"+fact1);
System.out.println("------------------------------------------------------------------");
Factorial f2=new Factorial();
System.out.println("Enter a number to find factorial of the number using recursion:");
//Reading input from user using scanner class object
int n2=sc.nextInt();
int fact2=f2.factorial2(n2);
System.out.println("The factorial of the number calculated using recursion is:"+fact2);
}
}

Output Screenshot:

Note: Every step is explained using comments in the program. Please save the file as Factorial.java and compile and execute the program using commands shown in the screenshot.