Useful functions that could be considered as extentions to Javascript

ext.js

/**
 * Given an Object it returns its length.
 * Much like returning the size of an 
 * associative array.
 * 
 * Usage:
 * ```js
 * var size = Object.size(myObject);
 * ```
 * 
 * @param obj Object any javascript object
 * 
 * @return integer the size of the object
 */
Object.size = function(obj) 
{
    var size = 0, key;
    for (key in obj) {
        if (obj.hasOwnProperty(key)) size++;
    }
    return size;
    
    // Better alternative?
    // return Object.keys(obj).length;
};

/**
 * Extends the Object prototype with the 
 * useful length() method which returns the
 * number of the object's attributes.
 * 
 * @return integer the number of attributes
 */
Object.prototype.length = function ()
{
    return Object.size(this);
    // return Object.keys(this).length;
}

var AssocArray = function ()
{
    this.length = 0;
    this.data = {};
}
AssocArray.prototype.set = function (key, value)
{
    this.data[key] = value;
}
AssocArray.prototype.get = function (key)
{
    return this.data[key];
}