Merge two sorted lists

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
  
           /* if(l1==null)
                    return l2;
            if(l2==null)
                    return l1;
                if(l1.val<l2.val)
                {
                        l1.next=mergeTwoLists(l1.next,l2);
                        return l1;
                }
                else
                {
                        l2.next=mergeTwoLists(l1,l2.next);
                        return l2;
                }*/
            
                ListNode dummy = new ListNode(0);
            ListNode l3 = dummy;
      
            while(l1!=null && l2!=null)
            {
                    if(l1.val<l2.val)
                    {
                            l3.next=l1;
                            l1=l1.next;
                    }
                    else
                    {
                            l3.next=l2;
                            l2=l2.next;
                    }
                    l3=l3.next;
            }
            
            if(l1!=null)
            {
                    l3.next=l1;
            }
            if(l2!=null)
            {
                    l3.next=l2;
            }
            
            return dummy.next;
                

        
    }
}