In this article, we will understand how to find the factorial of a number. Factorial of a number is the product of itself with each of its lower numbers.
Factorial is a function applied to natural numbers greater than zero. The symbol for the factorial function is an exclamation mark after a number, like this: 5!
Below is a demonstration of the same −
Input
Suppose our input is −
Enter the number : 5
Output
The desired output would be the following i.e. 5! = 5x4x3x2x1
The factorial of 5 is 120
Algorithm
Step1- Start Step 2- Declare three integers: my_input_1, factorial and i Step 3- Prompt the user to enter an integer value/ Hardcode the integer Step 4- Read the values Step 5- Run while loop, multiply the number with its lower number and run the loop till the number is reduced to 1. Step 6- Display the result Step 7- Stop
Example 1
Here, the input is being entered by the user based on a prompt. You can try this example live in ourcoding ground tool .
import java.util.Scanner; public class FindFactorial{ public static void main(String arg[]){ int my_input, factorial, i; System.out.println("Required packages have been imported"); Scanner my_scanner = new Scanner(System.in); System.out.println("A scanner object has been defined "); System.out.println("Enter a number: "); my_input = my_scanner.nextInt(); factorial=1; for(i=1;i<=my_input;i++){ factorial=factorial*i; } System.out.printf("The factoral of %d is %d" , my_input,factorial); } }
Output
Required packages have been imported A scanner object has been defined Enter a number: 5 The factorial of 5 is 120
Example 2
Here, the integer has been previously defined, and its value is accessed and displayed on the console
public class FindFactorial{ public static void main(String arg[]){ int my_input, factorial, i; my_input = 5; System.out.printf("The number is %d ",my_input ); factorial=1; for(i=1;i<=my_input;i++){ factorial=factorial*i; } System.out.printf("\nThe factorial of %d is %d" , my_input,factorial); } }
Output
The number is 5 The factorial of 5 is 120