JavaScript Class Best Practice?

Question

I'm currently looking into different patterns for building classes in JavaScript. But no matther what pattern I see, there are still some things I am not really sure about.

var ItemManager = (function()
{
    var p = function()
    {
        this.items= [];
    };

    p.prototype.addItem = function(item)
    {
        var self = this;    
        self.items.push(item);
    };

    return p;
}());

I create the simple class ItemManager, this class got the function addItem for adding any item to the collection. Now I don't really want the variable items, which represents the collection, to be public, this variable should be private, but I don't see any possible way to use a prototyped method to access private variables.

So what's the best practice in this case? Simply don't use private variables?

Answer 1

var ItemManager = function() {
    var items = [];

    return {
           addItem : function(item) {   
               items.push(item);
           },
           removeItem : function() {
                return items.pop();
           }
     }
};

var myItemManager = new ItemManager();

items variable becomes hidden after the execution of ItemManager function, but addItem and removeItem still share the access to items. See the Douglas Crockford's article on private variables in JavaScript for further investigation.