C Programs Tutorials | IT Developer
IT Developer

Java Programs

Share with a Friend
Previous
HOME
Next

Menu Driven - Factors/Factorial Program - Java Programs

Using the switch statement, write a menu-driven program to:
(i) To find and display all the factors of a number input by the user (including 1 and excluding the number itself).
Example:
INPUT:
n = 15
OUTPUT:
1, 3, 5
(ii) To find and display the factorial of a number input by the user. The factorial of a non-negative integer n, denoted by n!, is the product of all integers less than or equal to n.

Example:
INPUT:
n = 5
OUTPUT:
5! = 1 × 2 × 3 × 4 × 5 = 120.
For an incorrect choice, an appropriate error message should be displayed.

Java 

import java.util.Scanner;
class Menu{
    public static void main(String args[]){
        Scanner in = new Scanner(System.in);
        System.out.println("1. Display factors");
        System.out.println("2. Display factorial");
        System.out.print("Enter your choice: ");
        int choice = Integer.parseInt(in.nextLine());
        switch(choice){
            case 1:
            System.out.print("N = ");
            int n = Integer.parseInt(in.nextLine());
            for(int i = 1; i <= n; i++){
                if(n % i == 0)
                    System.out.println(i);
            }
            break;
            case 2:
            long f = 1L;
            System.out.print("N = ");
            n = Integer.parseInt(in.nextLine());
            for(int i = 1; i <= n; i++){
                f *= i;
            }
            System.out.println("Factorial: " + f);
            break;
            default:
            System.out.println("Invalid choice!");
        }
    }
}

Output

 
 OUTPUT 1: 
1. Display factors
2. Display factorial
Enter your choice: 1
N = 15
1
3
5
15
 
 OUTPUT 2: 
1. Display factors
2. Display factorial
Enter your choice: 2
N = 5
Factorial: 120
Previous
Next