Factorial of a number is the product of the numbers from 1 to that number. For example factorial of 3, denoted as 3! and the value is 3x2x1 = 6.

In java we can find a factorial in two ways, using for-loop and using function (calling recursively).

Finding Factorial Using for loop:

public static void main(String[] args){
    int var = 6;
    int result = 1;
    for (int i = 1; i <= var; i++)
        result = result * i;
    System.out.println("Factorial of " + var + " is " + result);
}

Finding Factorial Using Recursion

public class FactorialFinder {

    int factorial(int n){
        if(n==1) return 1;
        else return n*fact(n-1);
    }

    public static void main(String[] args) {
        int result = factorial(1);
        System.out.println("Factorial 1! = " + result);

        result = factorial(5);
        System.out.println("Factorial 5! = " + result);

        result = factorial(7);
        System.out.println("Factorial 7! = " + result);
    }
}

So you can practice on your compiler. Tank you.