PalindromeChecker.java

import java.util.Scanner;

public class PalindromeChecker {

    public static boolean isPalindrome(String str) {
        str = str.replaceAll("\\s+", "").toLowerCase();
        int left = 0, right = str.length() - 1;
        while (left < right) {
            if (str.charAt(left) != str.charAt(right)) {
                return false;
            }
            left++;
            right--;
        }
        return true;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a word or phrase: ");
        String input = sc.nextLine();

        if (isPalindrome(input))
            System.out.println("✅ It's a palindrome!");
        else
            System.out.println("❌ Not a palindrome.");

        sc.close();
    }
}