[LeetCode][JavaScript]Remove Linked List Elements

Remove Linked List Elements

Remove all elements from a linked list of integers that have value val.

Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> 5

https://leetcode.com/problems/remove-linked-list-elements/

 1 /**
 2  * @param {ListNode} head
 3  * @param {number} val
 4  * @return {ListNode}
 5  */
 6 var removeElements = function(head, val) {
 7     var res = new ListNode(-1);
 8     res.next = head;
 9     var current  = head;
10     var previous = res;
11     while(current !== null){
12         if(current.val === val){
13             previous.next = current.next;
14         }else{
15             previous = current;
16         }
17         current = current.next;
18     }
19
20     return res.next;
21 };