Simple Palindrome Detector [duplicate]

Answer 1

start==end always compares the same string. If the input is "cat", it checks if "cat"=="cat" which is true.

Use recursion if you are not allowed to use loops:

String input=in.nextLine();

isPalindrome(0,start.length()-1,input);

boolean isPalindrome(left,right,input){
   if (left>=right){
      // left==right for odd palindrome
      // left>right for even palindrome
      return true;
   }
   if (str.charAt(left)!=str.charAt(right)){
       return false;
   }
   return isPalindrome(left+1,right-1,str);
}