Question

(Palindrome integer) Write the methods with the following headers
	// Return the reversal of an integer, i.e., reverse(456) returns 654
	public static int reverse(int number)
	// Return true if number is a palindrome
	public static boolean isPalindrome(int number)

Use the reverse method to implement isPalindrome. A number is a palindrome if its reversal is the same as itself. Write a test program that prompts the user to enter an integer and reports whether the integer is a palindrome.

Here is a sample run: (red indicates a user input)

Enter a positive integer: 12321

12321 is a palindrome.

Continue? (y/n) y

Enter a positive integer: 12345

12345 is not a palindrome.

Continue? (y/n) n

Good bye!

This is for java if you could make it so it is debugged so theres no inputs that could make it crash! :(

Please leave comments

Answer 1

import java.util.Scanner;

public class PalindromeInteger {

    public static int reverseRecursive(int number) {
        int rev = 0;
        while (number > 0) {
            rev *= 10;
            rev += (number % 10);
            number /= 10;
        }
        return rev;
    }

    public static boolean isPalindrome(int number) {
        return reverseRecursive(number) == number;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        char choice;
        do {
            System.out.print("Enter a positive integer: ");
            int n = in.nextInt();
            if (isPalindrome(n)) {
                System.out.println(n + " is a palindrome.");
            } else {
                System.out.println(n + " is not a palindrome.");
            }
            System.out.print("Continue? (y/n) ");
            choice = in.next().charAt(0);
        } while (choice == 'y' || choice == 'Y');
        System.out.println("Good bye!");
    }
}