Palindrome

[Tarrell Fletcher]

Here is my code but I can't seem to get this phrase to output the same. The phrase is "A man a plan a canal panama"

import java.util.Scanner;
import java.util.*;



public class Palindrone{


	public static void main (String args[]){

			Scanner input = new Scanner (System.in);

			System.out.println("Welcome to the Palindrome Test");

			System.out.println("Type a word: ");
				String s1 = input.nextLine();
				String s2 = reverseIt(s1);
				System.out.println();

			if ( s1.equals(s2) ){
					System.out.println("This is a Palindrome: "+s1+s2);

			}// String comparison if
			else
				System.out.println("This is not a Palindrome");


	}// end main


	public static String reverseIt(String a) {

		int length = a.length();
		StringBuilder reverse = new StringBuilder();

		for(int i = length; i > 0; --i) {
			char result = a.charAt(i-1);
			reverse.append(result);
		}

			return reverse.toString();
}// end reverse



}// end test

[Paul Clapham]

Tarrell, I edited your code to use the "Code" tags. Looks a lot more readable, right? You can use them yourself in future, just click on the Code button and post your code between the tags you get.

Anyway, what exactly is your question? I would expect that code to output "This is not a Palindrome". Did it not do that? Or what were you expecting?

[dennis deems]

Well, the result of reverseIt is: amanap lanac a nalp a nam A. Right away we are in trouble because the String.equals will fail as soon as it compares 'A' to 'a'. So your comparison needs to be case-insensitive. After you solve that, the String.equals will fail when it compares 'm' to ' '.

Note that palindromes ignore case, spaces, and punctuation. This celebrated palindrome is often rendered as: "A man, a plan, a canal: Panama!". So before you begin your String comparison, you'll want to strip out anything that is not a letter.

[Harsha Smith]

Dennis Deems wrote: So before you begin your String comparison, you'll want to strip out anything that is not a letter.

Digits?

[Campbell Ritchie]

Harsha Smith wrote: . . . Digits?

If you are using words, yes. You can have numbers which you regard as palindromic, eg 12321, but that is a different problem.

[Tarrell Fletcher]

I found out how to fix it. I just needed to close up any whitespace so when I typed a word with a space it wouldn't see that blank. My assignment was to show the reversed code with no spaces so I guess that was it.