JAVA PROGRAM TO FIND FACTORIAL OF A GIVEN NUMBER

FACTORIAL : Factorial is a mathematical term that is used to calculate the product of an integer. Factorial of a number n can be calculated as n! (here value of n! is 1*2*3*4 ... (n-1)*n)

Assume you have to calculate the factorial of a number say 6, its factorial can be calculated as 5!= 5 *4 * 3 * 2 * 1 which is equal to 120. Lets see the implementation with Java program.

Example 1 : Java Program of Factorial using For Loop

// Java program to calculate factorial of any number
import java.util.Scanner;
class FactorialDemo{
    static int findfactorial(int n){
       int fact=1;
	  
       for(int i=n ; i>0 ; i-- ) {
           fact= fact*i;
       }
       return fact;		
    }
}

public class Codebator{
    public static void main(String[] args) {
       Scanner sc=new Scanner(System.in);
       System.out.println("Enter any Number");
       int num=sc.nextInt();
       int result=FactorialDemo.findfactorial(num);
       System.out.println("Factorial of the given number s : "+result);
   }
}

Enter any Number5 120 

Example 2 : Java Program of Factorial using While Loop

// Java program to calculate factorial of any number
import java.util.Scanner;
class FactorialDemo{
    static int findfactorial(int n){
       int fact = 1,i=1;
	  
       while(i <= n) {
         fact = fact * n;
         n--;
       }	
       return fact;
    }
}

public class Codebator{
    public static void main(String[] args) {
       Scanner sc=new Scanner(System.in);
       System.out.println("Enter any Number");
       int num=sc.nextInt();
       int result=FactorialDemo.findfactorial(num);
       System.out.println("Factorial of the given number s : "+result);
   }
}

Enter any Number7 5040 

Example 2 : Java Program of Factorial using Recursion

// Java program to calculate factorial of any number
import java.util.Scanner;
class FactorialDemo{
    static int findfactorial(int n){
      if (n == 0)    
         return 1;    
      else    
         return(n * findfactorial(n-1));   
    }
}

public class Codebator{
    public static void main(String[] args) {
       Scanner sc=new Scanner(System.in);
       System.out.println("Enter any Number");
       int num=sc.nextInt();
       int result=FactorialDemo.findfactorial(num);
       System.out.println("Factorial of the given number s : "+result);
   }
}

Enter any Number8 40320 

Some useful links :

• 1. Java Inheritance
• 2. Method Overloading in Java
• 3. Method Overriding in Java
• 4. Super keyword in Java