Implementation of linked list in javascript

Singly Linked List.js

function singlyLinkedList() {
  this.length = 0; //Default value
  this.head = null;
}

//To store in a new node
function storeNode(data) {
  this.data = data;
  this.next = null;
};

//To add a node
singlyLinkedList.prototype.add = function(value) {
  var node = new storeNode(value);
  var currentNode = this.head;

  //If current node is null, then its a new list
  if (!currentNode) {
    this.head = node; //Set new node as current node

    this.length++; //Increment length of list

    return node;
  }

  //If next presents, then set current node to next node
  while(currentNode.next) {
    currentNode = currentNode.next;
  }

  currentNode.next = node; //Set next node as newly created node

  this.length++;

  return node;
};

var list = new singlyLinkedList();
list.add(1); //Head
list.add(2); //1st node has ref of this node, this node ref = null

singlyLinkedList.prototype.remove = function(position) {
  var currentNode = this.head;
  var deletedNode  = null;
  var nextToDelete  = null;
  var beforeToDelete  = null;
  var count = 0;

  //If position not present
  if (position < 0 || position > list.length) {
    throw new Error("Invalid position");
  }

  //If position is head's position
  if (position === 1) {
    this.head = currentNode.next; //Set next node to head
    deletedNode = currentNode; //To return deleted node
    this.length--; //Decrement the length

    return deletedNode;
  }

  //If any other position
  while (count < position) {
    beforeToDelete = currentNode;
    nextToDelete = currentNode.next;
    count++;
  }

  beforeToDelete.next = nextToDelete.next; //Before removing node
  deletedNode = nextToDelete;
  nextToDelete = null;
  this.length--; //Decrement length after deleting
  return deletedNode;
};

singlyLinkedList.prototype.search = function(position) {
  var currentNode = this.head;
  var count = 1;

  //If list is empty or position invalid or position not present
  if (this.length < 0 || position > this.length || position < 0) {
    throw new Error("Invalid position");
  }

  //If position present, return its node
  while (count < position) {
    currentNode = currentNode.next; //Set currentNode to next node
    count++;
  }

  return currentNode;
};

How to free the space that is allocated to deleted node in singlyLinkedList.prototype.remove?