Iterative Constructs in Java

Chapter 9

Iterative Constructs in Java

Class 10 - Logix Kips ICSE Computer Applications with BlueJ

Share with a Friend

HOME

Java Program: Menu Driven Program - Palindrome and Perfect Number Checker

31. Write a menu driven class to accept a number from the user and check whether it is Palindrome or a Perfect number.

(1). Palindrome number: A number is a Palindrome which when read in reverse order is same as read in the right order Example: 11, 101, 151, etc.

(2). Perfect number: A number is called Perfect if it is equal to the sum of its factors other than the number itself.
Example: 6 = 1 + 2 + 3

Program Title: Palindrome and Perfect Number Checker

Java

import java.util.Scanner;
 
public class NumberChecker {
 
    // Method to check if a number is Palindrome
    public static boolean isPalindrome(int num) {
        int original = num;
        int reverse = 0;
 
        while (num != 0) {
            int digit = num % 10;
            reverse = reverse * 10 + digit;
            num /= 10;
        }
 
        return original == reverse;
    }
 
    // Method to check if a number is Perfect
    public static boolean isPerfect(int num) {
        int sum = 0;
        for (int i = 1; i <= num / 2; i++) { // only factors less than num
            if (num % i == 0) {
                sum += i;
            }
        }
        return sum == num;
    }
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        System.out.println("Menu:");
        System.out.println("1. Check Palindrome");
        System.out.println("2. Check Perfect Number");
        System.out.print("Enter your choice: ");
        int choice = sc.nextInt();
 
        System.out.print("Enter a number: ");
        int number = sc.nextInt();
 
        switch (choice) {
            case 1:
                if (isPalindrome(number)) {
                    System.out.println(number + " is a Palindrome number.");
                } else {
                    System.out.println(number + " is not a Palindrome number.");
                }
                break;
 
            case 2:
                if (isPerfect(number)) {
                    System.out.println(number + " is a Perfect number.");
                } else {
                    System.out.println(number + " is not a Perfect number.");
                }
                break;
 
            default:
                System.out.println("Invalid choice! Please select 1 or 2.");
        }
 
        sc.close();
    }
}

Output

Sample Output 1 (Palindrome)
Menu:
1. Check Palindrome
2. Check Perfect Number
Enter your choice: 1
Enter a number: 121
121 is a Palindrome number.

Sample Output 2 (Perfect Number)
Menu:
1. Check Palindrome
2. Check Perfect Number
Enter your choice: 2
Enter a number: 28
28 is a Perfect number.

How It Works

Palindrome Check: Reverse the number and compare with original.
Perfect Number Check: Sum all factors less than the number and compare with the number.
Menu Driven: Switch-case to choose between the two options.