var PubSub = {
  subscribe: function(ev, callback) {
    //create this._callbacks object if not exist.
    var calls = this._callbacks || (this._callbacks = {});

    //create this._callbacks events array if not exist
    //add callback function to this._callbacks[ev]
    (this._callbacks[ev] || (this._callbacks[ev]=[])).push(callback);

    //return Pubsub
    return this;
  },

  publish: function() {
    console.log('publish:', arguments);

    // convert arguments to array, so can shift it.
    var args = Array.prototype.slice.call(arguments, 0);

    // get event name (first arg)
    var ev = args.shift();

    var list, calls, i, l;

    // this._callbacks is non object?
    if(!(calls = this._callbacks)) return this;

    // this._callbacks[ev] not exist?
    if(!(list  = this._callbacks[ev])) return this;

    // execute callback
    for(i=0, l=list.length; i<l; i++) {
        list[i].apply(this, args);
    }
    return this;
  }
}
//testing:
PubSub.subscribe('event1', function() { console.log('callback 1'); });
PubSub.subscribe('event2', function(val) { console.log('callback 2: ' + val); });
PubSub.subscribe('event3', function(ary) { console.log('callback 3', ary); });

PubSub.publish('event1');  //callback 1
PubSub.publish('event2', 123);  //callback 2: 123
PubSub.publish('event3', [1,2,3]); //callback 3 [1, 2, 3] 

var animals = [
  {species: 'Lion', name: 'King'},
  {species: 'Whale', name: 'Fail'}
];
#0 Lion: King VM14706:10
#1 Whale: Fail
for (var i = 0; i < animals.length; i++) {
  (function (i) {
    this.print = function () {
      console.log('#' + i  + ' ' + this.species
                  + ': ' + this.name);
    }
    this.print();
  }).call(animals[i], i);
}
#0 Lion: King VM14706:10
#1 Whale: Fail 

(function($) {
  var o = $({});

  $.subscribe = function() {
    o.bind.apply(o, arguments);  //or on:
  };

  $.unsubscribe = function() {
    o.unbind.apply(o, arguments); //or off:
  };

  $.publish = function() {
    //['event2', 123]
    //var args = [].splice.call(arguments, 1,1);
    //args = [].splice.call(arguments, 0);
    //o.trigger.apply(o, args);
    o.trigger.apply(o, arguments);
  }
})(jQuery);

//testing:
$.subscribe('topic', function(event, a,b,c) {
  console.log(event.type, b,c,a);
});
$.publish('topic', {a:'b'}, ['aa', 'bb', 'cc']);
//'topic', aabbcc