Factorial

 package code.mypack;

import java.util.Scanner;

public class src {

public static void main(String[] args) {

    System.out.println("Enter n:");

Scanner sc=new Scanner(System.in);

int n=sc.nextInt();

int fact=1;

for(int i=1;i<=n;i++){

    fact=fact*i;

}

System.out.println(fact);

}

OR

WHILE LOOP

 package code.mypack;

import java.util.Scanner;

public class src {

    public static void main(String[] args) {

        System.out.println("Enter n:");

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int fact = 1;

        int i = 1;

        while (i <= n) {

            fact = fact * i;

            i++;

        }

        System.out.println(fact);

    }

}