Factorial.java

import java.util.Scanner;

public class Factorial {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a non-negative integer to calculate its factorial: ");
        int number = scanner.nextInt();
            long factorial = calculateFactorial(number);
            System.out.println("The factorial of " + number + " is " + factorial);
    }

    public static long calculateFactorial(int n) {
        if (n == 0 || n == 1) {
            return 1;
        } else {
            long result = 1;
            for (int i = 2; i <= n; i++) {
                result *= i;
            }
            return result;
        }
    }
}