Merge Two Sorted Lists

Merge two sorted linked lists and return it as a new sorted 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

class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1 == null)
            return l2;
        if (l2 == null)
            return l1;
        ListNode p1 = l1, p2 = l2, ans = new ListNode(0), ansPointer = ans;
        while (p1 != null && p2 != null) {
            if (p1.val <= p2.val) {
                ansPointer.next = p1;
                p1 = p1.next;

            } else {
                ansPointer.next = p2;
                p2 = p2.next;
            }
            ansPointer = ansPointer.next;
        }
        if (p1 != null)
            ansPointer.next = p1;
        if (p2 != null)
            ansPointer.next = p2;
        return ans.next;
    }
}