String is palindrome or not using recursion. GFG

 package com.company;

public class CWR_Gfg_Recursion_SumOfNNaturalNo {
//    Sum of n natural numbers using recursion
    public static int sum(int n){
        if(n == 0){
            return 0;
        }
        return n + sum(n-1);
    }

//    Checking a String is palindrome or not  by using recursion
    public static boolean isPalindrome(String s, int start, int end){
        if(start >= end){
            return true;
        }
        return ( s.charAt(start) == s.charAt(end) ) && isPalindrome(s,start+1, end-1);

    }
    public static void main(String[] args) {
//        System.out.print(sum(100));
        System.out.println(isPalindrome("123321",0,5));
    }
}