LeetCode21-Merge-Two-Sorted-Lists

Merge two sorted linked lists and return it as a new list. The new
list should be made by splicing together the nodes of the first two
lists.

Example:

Input: 1->2->4, 1->3->4 Output: 1->1->2->3->4->4

public ListNode mergeTwoLists(ListNode l1, ListNode l2) {    ListNode trueHead=new ListNode(0);    ListNode cur=trueHead;    while(l1!=null || l2!=null){        if(l1==null){            cur.next=l2;            l2=l2.next;        }else if(l2==null){            cur.next=l1;            l1=l1.next;        }else if(l1.val<=l2.val){            cur.next=l1;            l1=l1.next;        }else{            cur.next=l2;            l2=l2.next;        }        cur=cur.next;    }       return trueHead.next;    }