linked list javascript implementation

linkedlist.js

var Node = function(value){
  var node = {};

  node.value = value;
  node.next = null;

  return node;
};

var LinkedList = function(){
  var list = {};
  list.head = null;
  list.tail = null;

  var listItems = {};
  list.listItems = listItems;

  var itemCount = 0;

  list.addToTail = function(value){
    var newNode = new Node();
    newNode.value = value;

    listItems[itemCount] = newNode;
    list.tail = newNode;

    // for adding first Node
    if(list.head == null){
      list.head = newNode;
    } else {
      listItems[itemCount-1].next = itemCount;
    }

    itemCount++;
  };

  list.removeHead = function(){
    delete listItems[0];
    for(var i = 0; i < itemCount; i++){
      if(i == itemCount - 1){
        break;
      } else {
        listItems[i] = listItems[i+1];
        if(listItems[i].next !== null){
          listItems[i].next -= 1;
        }
        delete listItems[i+1];
      }
    }
    itemCount--;
    list.head = listItems[0];
    list.tail = listItems[itemCount-1];
  };

  list.contains = function(target){

    for(var i = 0; i < itemCount; i++){
      // if target string is equal to value property of a Node
      if(listItems[i].value === target){
        return true;
      }
    }

    return false;
  };

  return list;
};


// Tests
// ======
var myList = new LinkedList();
myList.addToTail('item one');

myList.removeHead();
myList.addToTail('item two');
myList.addToTail('item three');
myList.addToTail('item four');

console.log(myList);