for kory baby <3

Palindrome.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DecimalFormat;
import java.util.StringTokenizer;

public class Palindrome {

    public static void main(String[] args) throws IOException {

        // Setup a new BufferedReader to read user input.
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        // Prompt the user to enter a phone number.
        System.out.println("Enter a phone number:");

        // Create a new StringBuffer for the inputted phone number.
        String inputtedPhoneNumber = br.readLine();

        // Clean the phone number, removing any punctuation, or white space.
        String cleanedPhoneNumber = cleanPhoneNumber(inputtedPhoneNumber);

        // Display the cleaned phone number.
        System.out.println("Cleaned phone number: " + cleanedPhoneNumber);

        // Display whether or not the phone number is a palindrome.
        System.out.println("Is a palindrome: " + isPalindrome(cleanedPhoneNumber));

        // Lastly, output the number in comma form.
        System.out.println("Phone number in comma form: " + convertToCommaForm(cleanedPhoneNumber));
    }

    /**
     * cleanPhoneNumber
     *
     * Accepts a StringBuffer dirtyPhoneNumber and sanitizes it
     * to be a String of digits with no punctuation.
     *
     * @param dirtyPhoneNumber
     * @return String
     */
    public static String cleanPhoneNumber(String dirtyPhoneNumber){

        // Create a new StringTokenizer to break the dirtyPhoneNumber string apart into tokens.
        StringTokenizer tokenizer = new StringTokenizer(dirtyPhoneNumber, " ");

        // First, extract the area code from the first token.
        StringBuffer areaCode = new StringBuffer(tokenizer.nextToken())
                .deleteCharAt(0)
                .deleteCharAt(3);

        // Get the second token, which is the remaining part of the phone number.
        String phoneNumber = tokenizer.nextToken();

        // Delete the '-' at position 3, again we know it's position 3 since the phone
        // numbers are all inputted in the same fashion.
        tokenizer = new StringTokenizer(phoneNumber, "-");

        String cleanPhoneNumber = tokenizer.nextToken() + tokenizer.nextToken();

        // Return the cleaned area code, concatenated with the remaining phone number
        return areaCode + cleanPhoneNumber;
    }

    /**
     * isPalindrome
     *
     * Determines whether or not the inputted String, cleanedPhoneNumber, is
     * a palindrome or not.
     *
     * @param cleanedPhoneNumber
     * @return boolean
     */
    public static boolean isPalindrome(String cleanedPhoneNumber){
        // Create an empty StringBuffer object to store the reversed string
        StringBuffer reversedPhoneNumber = new StringBuffer(cleanedPhoneNumber.length());

        // Reverse the string
        for(int i = 1; i <= cleanedPhoneNumber.length(); i++){
            reversedPhoneNumber.append(cleanedPhoneNumber.charAt(cleanedPhoneNumber.length() - i));
        }

        // Return the result of a call to the equals method on the String class, to see if these two
        // phone numbers are equal.
        return reversedPhoneNumber.toString().equals(cleanedPhoneNumber);
    }

    /**
     * convertToCommaForm
     *
     * Converts the inputted String, cleanedPhoneNumber, to be a long, comma
     * separated number.
     *
     * @param cleanedPhoneNumber
     * @return
     */
    public static String convertToCommaForm(String cleanedPhoneNumber){
        // Parse the cleanedPhoneNumber String for a long number.
        long number = Long.parseLong(cleanedPhoneNumber);

        // Create a new DecimalFormatter object to format the long number,
        // matching the pattern specified to the constructor.
        DecimalFormat decimalFormatter = new DecimalFormat("#,###,###,###");

        // Return the formatted number from the DecimalFormatter
        return decimalFormatter.format(number);
    }

}