Remove duplicates from sorted list [https://leetcode.com/problems/remove-duplicates-from-sorted-list/]

remove_duplicates_from_sorted_list.js

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var deleteDuplicates = function(head) {
    if (!head) {
        return head;
    }

    let newList = {
        val: head.val,
        next: null,
    };
 
    let newListReference = newList;
    let currentReference = head.next;

    while (currentReference) {
        if (currentReference.val !== newListReference.val) {
            // take the item
            let newItem = {
                val: currentReference.val,
                next: null,
            };

            newListReference.next = newItem;
            newListReference = newItem;
        }

        // go to the next node
        currentReference = currentReference.next;
    }

    return newList;
};