inheritance.js

var Car = function () {
    // private
    var that = null,
        defaultColor = 'red'
    ;

    // public
    return {
        color: '',
        init: function (c) {
            that = this;
            this.color = (typeof (c) !== 'undefined') ? c : defaultColor;
        },

        getColor: function () {
            return that.color;
        },

        getDefaultColor: function () {
            return defaultColor;
        }
    }
};

var SportsCar = function () {
    // private
    var that = null,
        horsepower = -1
    ;

    // public
    return {
        init: function (legalGuardian, hp) {
            that = this;
            $.extend(true, this, legalGuardian);
            horsepower = hp;
        },

        getHp: function () {
            return horsepower;
        }
    }
}

var LuxurySportsCar = function () {
    // private
    var that = null,
        diamonds = -1
    ;

    // public
    return {
        init: function (legalGuardian, dm) {
            that = this;
            $.extend(true, this, legalGuardian);
            diamonds = dm;
        },

        printStats: function () {
            console.log('defaultColor: ' + this.getDefaultColor());
            console.log('color: ' + this.getColor());
            console.log('horsepower: ' + this.getHp());
            console.log('diamonds: ' + diamonds);
        }
    }
}

$(function () {
    var car = new Car();
    car.init('blue');

    var s = new SportsCar();
    s.init(car, 390);

    var lux = new LuxurySportsCar();
    lux.init(s, 200);

    lux.printStats();

});