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

removeListElements.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
 * @param {number} val
 * @return {ListNode}
 */
var removeElements = function(head, val) {
    const dummy = { next: head };
    
    let [prev, curr] = [dummy, head];
    while(curr){
        if(curr.val === val) prev.next = curr.next;
        else prev = curr;
        curr = curr.next;   
    }
    
    return dummy.next;
};