// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/create-a-linked-list-class

function LinkedList() {
  var length = 0;
  var head = null;

  var Node = function (element) {
    this.element = element;
    this.next = null;
  };

  this.head = function () {
    return head;
  };

  this.size = function () {
    return length;
  };

  this.add = function (element) {
    // Only change code below this line
    const newNode = new Node(element);
    length++;
    let current = head;
    if (current === null) {
      head = newNode;
      return;
    }
    while (current.next !== null) {
      current = current.next;
    }
    current.next = newNode;
    // Only change code above this line
  };
}