LeetCode: Reverse a String in java with O(1) space

 public class ReverseString {

    public static void reverseString(String str) {
      char[] s =str.toCharArray();

        int left = 0, right = s.length - 1;
        while (left < right) {
            char tmp = s[left];
            s[left++] = s[right];
            s[right--] = tmp;
        }

        System.out.println(String.valueOf(s));
    }

    public static void main(String[] args) {
        reverseString("ramu is a good boy");
    }
}