Factorial of a given number

Factorial is a positive integer that is the result of the multiplication of all integers that are less than equal to the given number.

For example, the Factorial of 5 is 54321=120.

Using Iterative Function

Following are steps for the Iterative function.

  • Used for loop to iterate until give number is matched.
  • Declared temporary variable(result) that holds result, with default value 1
  • Multiply the result with each iterated value and assign it to result
  • Finally, Return the result

Here is a program in java

public class Factorial {
    public static void main(String[] args) {
        int number = 5;
        System.out.println(iterative(number));

    }
    // Iterative Function
    public static int iterative(int n)
    {
        int result = 1;
        for (int i = 1; i <= n; i++)
            result *= i;
        return result;
    }
}

Output:

120

Using Recursive Function

Following are the steps

  • Write a function that returns an integer
  • Write a condition to stop the execution from a function
  • Multiplication of numbers with a recursive function.
  • Recursive Function call itself with decrement value by 1,
  • Finally, Returns the result.
package com.recursion;

public class Factorial {
    public static void main(String[] args) {
        int number = 5;
        System.out.println(recursive(number));

    }
    // Recursive Function
    public static int recursive(int n) {
        if ((n == 0) || (n == 1))
            return 1;
        else {
            return n * recursive(n - 1);
        }
    }
}

Output:

120