its giving true for both values in boolean. how to improve the code?

Question

import java.util.Scanner;

class Pal {
    public static boolean Palindrome(StringBuffer str) {
        StringBuffer str1 = str.reverse();
        System.out.println(str1);
        if (str == str1) {
            return true;
        } else { 
            return false;
        }
    }

    public static void main(String args[]) {
        System.out.println("Enter a string");

        StringBuffer str = new StringBuffer();
        Scanner input = new Scanner(System.in);
        str.append(input.nextLine());

        boolean result = Palindrome(str);
        System.out.println(result);
    }
}

How sholud I improve my code such that values come out to be perfectly correct?

try using .equals() method instead of == operator in your if condition to compare. — Dipen Adroja, Sep 03 '15 at 07:20
@BobTheBuilder did you read the whole question before marking this as a duplicate ? — Suresh Atta, Sep 03 '15 at 07:22

score 1 · Answer 1 · edited May 23 '17 at 11:44

if (str == str1)
{
  return true;
}
else
{ 
  return false;
}

is the same as

return str == str1;

However, this still "won't work" correctly because

Code should equals() for comparing objects (including Strings and StringBuffers) and
StringBuffer does not have a useful equals.

A correction, taking both of these into account, would be:

return str.toString().equals(str2.toString());

In this case we first get the current String content of both StringBuffer objects and then compare it with String.equals(String), which works as expected.

An alternative would be to bypass the StringBuffers in this case and directly use Strings; this would allow skipping the toString calls.

i tried this but this also didn't give me the correct answer. — Twinkle Lavania, Sep 05 '15 at 18:16

its giving true for both values in boolean. how to improve the code?

1 Answers1