Factorial of a Number in Java

In this post, you will learn how to find out the factorial of a number in Java.

Factorial :

Factorial of a number is the multiplication of all smaller integers than the number, 
including the number itself.

We can write factorial of a number as,

Solution :

There are mainly two ways to write the factorial program in Java:

1. Factorial using loop.
2. Factorial using recursion.

Approach 1 : Factorial using Loop

public class B{
    public static void main(String[] args) {
        int number = 5; // Replace with the desired number

        int fact = 1;
        for (int i = 1; i <= number; i++) {
            fact *=i;
        }

        System.out.println("The factorial of " + number + " is: " + fact);
    }
}

Output :

The factorial of 5 is: 120

Approach 2 : Factorial using Recursion

public class FactorialCalculator {
    public static void main(String[] args) {
        int number = 5; // Replace with the desired number

        int factorial = calculateFactorial(number);

        System.out.println("The factorial of " + number + " is: " + factorial);
    }

    public static int calculateFactorial(int n) {
        if (n == 0) {
            return 1;
        } else {
            return n * calculateFactorial(n - 1);
        }
    }
}

Output :

The factorial of 5 is: 120

More basic Java Programs:

Java Program to Print Multiplication Table of a Number

Java program to Count the Total number of Characters in a String

Java Program to Display Fibonacci Series

Prime Number Program in Java