Question

Please Help! (Language= Java) Beginners Comp. Science

Assignment Details=

Create a class called Palindromes, which will determine if a user’s entry is a palindrome. A
palindrome is a word or phrase that reads the same backwards or forwards. See the examples.
A Santa at NASA My gym taco cat kayak NOW I WON race car
Your program will ignore spaces and ignore case when determining if a string is a palindrome.
Use the String method replace to remove the spaces. If it is a palindrome, output
PALINDROME, or else output NOT PALINDROME.
Additional requirements:
 Add an infinite loop with a sentinel-trigger break test (allowing them to input multiple
attempts). You may decide on its command word or exit-condition.
 As below, make sure a spacer line exists between each run of the program
Here are two sample runs of the program.
Enter a word or phrase: Noon
PALINDROME
Enter a word or phrase: bookkeeper
NOT PALINDROME

Answer 1

import java.util.Scanner;

class Main {

public static void main(String[] args) {

test("A Santa at NASA");

test("My gym");

test("taco cat");

test("kayak");

test("NOW I WON");

test("race car");

test("bookkeeper");

Scanner scanner = new Scanner(System.in);

while(true) {

System.out.print("Enter a word or phrase: ");

String line = scanner.nextLine();

if (line.equals("exit")) break;

if (Palindromes.isPalindrome(line)) {

System.out.println("PALINDROME");

} else {

System.out.println("NOT PALINDROME");

}

}

scanner.close();

}

public static void test(String s) {

System.out.printf("'%s' is %sa palindrome\\", s, Palindromes.isPalindrome(s) ? "" : "not ");

}

}

class Palindromes {

static boolean isPalindrome(String s) {

s = s.replaceAll("\\s","").toLowerCase();

return s.equals(reverseString(s));

}

public static String reverseString(String str){

StringBuilder sb = new StringBuilder(str);

sb.reverse();

return sb.toString();

}

}

Step-by-step explanation:

I chose to use a string reverse routine. This is slightly less efficient than iterating the string from both ends, but performance is less important than readability here.

The stop word is exit.