JS Prototypes

app.js

(function () {
    function object(parent) {

        function F() {};
        F.prototype = parent || Object;
        return new F();
    }

    var Stack = function() {
        this.data = [];

        this.push = function(x) {
            this.data.push(x);
        };

        this.pop = function() {
            return this.data.pop();
        };
    };

    var CountedStack = function() {
        this.data  = [];
        this.count = 0;

        this._super = {};
        this._super.push = this.push;

        this.push = function() {
            this.count++;
            this._super.push.apply( this, arguments );
        };

        this.countPushes = function() {
            return this.count;
        };

    };

    CountedStack.prototype = new Stack();

    var c1 = new CountedStack();
    var c2 = new CountedStack();

    c1.push(7);
    c2.push(10);

    console.log(c1.pop());
    console.log(c1.countPushes());

}());