Shopkeeper Script Error

I was looking for a shopkeeper script to use in my game, I found this one: http://answers.unity3d.com/questions/509609/how-to-debug-this-shopkeeper-script-.html. but I don’t understand one line:

var shopList : List.<ItemClass> = new List.<ItemClass>(); // this is where all the items for shops are listed

What is List.ItemClass, shouldn’t it be an Array? I get this error about it:

Assets/Scripts/Main Scene/Shopkeeper.js(8,22): BCE0018: The name 'ItemClass' does not denote a valid type ('not found'). 

Can someone tell me what is wrong?

EDIT:
The whole script is:

#pragma strict

var hit : RaycastHit;
var shopOpen : boolean = false;
var texture : Texture2D;
var shopSize = Rect(50, 50, 400, 500);
var items : int[]; //This is where I put the item numbers for every shopkeeper
var shopList : List.<ItemClass> = new List.<ItemClass>(); // this is where all the items for shops are listed
var myTransform : Transform; //current transform data of this enemy
var target : Transform;
var shopDistance : int = 5;
private var slotNR : int = 0;
 
function Awake (){
    myTransform = transform; //cache transform data for easy access/preformance
}
 
function Start (){
    target = GameObject.FindWithTag("Player").transform; //target the player
}
 
function OnGUI () {
    if(shopOpen == true){
       shopSize = GUI.Window(3, shopSize, ShopWin, texture);
    }
}
 
function Update () {
    var distance = (target.position - myTransform.position).magnitude;
    if(distance < shopDistance){
       if(Input.GetMouseButtonDown(0) &&
            collider.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit, Mathf.Infinity)) {
            //enable shop    
            shopOpen = true;
       }
    }
//  if(distance > shopDistance){
//   shopOpen = false;
//  }
}
 
function ShopWin(){
    if(GUI.Button(Rect(375, 0, 25, 25), "X")){
       shopOpen = false;
    }
    // For recognizing the slot
    slotNR = 0;
    //y is row nr
    for(var y = 0; y < 2; y++){
       GUILayout.BeginHorizontal();
       //x is columnt nr
       for(var x = 0; x < 6; x++){
         xPosition = 12 + (x * 62);
         yPosition = 30 + (y * 62);
         //Shop slots. If clicked they check what item it is in the slot and then corresponds to it
         if(GUI.Button(Rect(xPosition, yPosition, 60, 60), shopList[items[slotNR]].icon)){
          Inventory.Coins -= 50;
          Inventory.playerInventory.Add(shopList[items[slotNR]]);
          return;
         }
         slotNR++;
       }
       GUILayout.EndHorizontal();
    }
 
    GUI.DragWindow();
}

List is a collection of certain data. Like array, only it has some distinctive properties.

Your list is a collection of object of type “ItemClass”. It seems like you are missing “ItemClass” class. Now, either you didnt copy it OR (more likely judging from the name) you have to create the class yourself.