[code=php]
import java.util.Scanner;

public class Main {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
System.out.print("Factorial을 구할 수는 : ");
int number = sc.nextInt();
int factorialsum = factorial(number);
System.out.println(number + "! = " + factorialsum);

}

private static int factorial(int number) {

int sum = 1;
for (int i = 2; i<= number; i++) {
sum = sum * i; //sum *= i;
}
return sum;

}

}
[/code]

재귀함수를 사용하여 구하기...

[code=php]
import java.util.Scanner;

public class Main {

private static Scanner sc;

public static void main(String[] args) {

sc = new Scanner(System.in);
System.out.print("Factorial을 구할 수는 : ");
int number = sc.nextInt();
int factorialsum = factorial(number);
System.out.println(number + "! = " + factorialsum);

}

private static int factorial(int number) {

if (number ==1) {
return 1;
} else {
return number * factorial(number -1);
}

}

}
[/code]