**Java Factorial Program:** Factorial of n is the product of all positive integers. n is denoted by n!. For example:

6! = 6*5*4*3*2*1 = 720

4! = 4*3*2*1 = 24

Here, 6! is pronounced as “4 factorial”, it is also called “6 bang” or “6 shriek”.

In java language many ways to write the factorial program . Let’s see the “TWO” ways to write the factorial program in java.

(i)Factorial Program using loop

(ii)Factorial Program using recursion

**(i)By using for loop write the Factorial Program:**

class FactorialExp1{

public static void main(String args[]){

int K,factorial=1;

int num=6;//It is the number to calculate factorial

for(K=1;K<=number;K++){

factorial=factorial*K;

}

System.out.println(“Factorial of “+num+” is: “+factorial);

}

}

**Output:**

** factorial of 6 is 720**

**(ii)Using recursion Write the Factorial Program in java :**

class FactorialExp2{

static int factorial(int number){

if (number == 0)

return 1;

else

return(number * factorial(number-1));

}

public static void main(String args[]){

int j,factorial=1;

int num=5;//It is the number to calculate factorial

factorial = factorial(num);

System.out.println(“Factorial of “+num+” is: “+factorial);

}

}

**Output:**

**factorial of 5 is 120**