Java Program to Print Factorial of a Number

Write a java program to print factorial of a number. In this tutorial, we are going to write a java code to print factorial of a number.

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C program to print factorial of a Number

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Java programs

Java Program to Print Factorial of a Number 

package factorial;

import java.util.*;


public class Factorial {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        int num, fact = 1;
        
        Scanner in = new Scanner(System.in);
        
        System.out.println("Enter a number ");

        /* Taking input from user */
        
        num = in.nextInt();
        
        /* If input number is greater than zero */
        
        if (num > 0) {
        /**
         * Suppose if user has input 4
         * 4 * 3 * 2 * 1
         */
        
            for (int i = 1; i <= num; i++) {
            
                fact = fact * i;
            
            }
        
            System.out.println("Factorial of a number is "+ fact);

        } else if ( num == 0) {
            System.out.println ("Factorial of a zero is 1");
            
        } else if (num < 0) {
            System.out.println("Factorial of a negative number doesn't exist");
        }
    }
    
}

Output :

Enter a number to calculate it's factorial  :   5

Factorial of a input number is : 120


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