Add Two Numbers

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

code:

public class add2Numbers {

    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

        ListNode iter1 = l1, iter2 = l2, newList = new ListNode(0), tail = newList;

        int carry = 0, sum;

        

        while(iter1 != null || iter2 != null){

            sum = carry;

            

            if(iter1 != null){

                sum += iter1.val;

                iter1 = iter1. next;

            }

            

            if(iter2 != null){

                sum += iter2.val;

                iter2 = iter2.next;

            }

            

            carry = sum / 10;

            sum %= 10;

            

            tail.next = new ListNode(sum);

            tail = tail.next;

        }

        

        if(carry != 0){

            tail.next = new ListNode(carry);

        }

        

        return newList.next;

    }

}