Java - Factorial of a Number using Recursion

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We can write a program to find the factorial of a given number using recursion and with out using recursion.

4! means = 1 * 2 * 3 * 4 = 24
5! means = 1 * 2 * 3 * 4 * 5 = 120  or (5 * 4!)
6! means = 1 * 2 * 3 * 4 * 5 * 6 = 720 or (6 * 5!)

Recursion meaning the function calls itself.

Source Code

import java.io.*;

class Facotorial_Recursive {

      public static long Fact(long n)

      {

            if (n <= 1)

                  return n;

            return n * Fact(n - 1);

      }

    public static void main(String[] args) {

            String inpstring = "";

            InputStreamReader input = new InputStreamReader(System.in);

            BufferedReader reader = new BufferedReader(input);

            try

            {

                  System.out.print("Enter a Number to Find Factorial:");

                  inpstring = reader.readLine();

                  long n = Long.parseLong(inpstring);

                  long result = Fact(n);

                  System.out.println("Facorial of " + n + " is " + result);

            }

            catch (Exception e)

            {

                  e.printStackTrace();

            }

    }

}

Output

C:\Java\Samples>javac Factorial_Recursive.java

C:\Java\Samples>Java Factorial_Recursive

Enter a Number to Find Factorial: 5

Factorial of 5 is 120