JavaScript Watch Object property changes

I've started with Eligrey's Gist and modified it a bit.

What it does

It monitors javascript objects and fires a callback once some property changes. You can use it to trigger functions when some property in some object changes

General syntax

someObject.watch(callback,propsToWatch);// start watchingsomeObject.unwatch(propsToUnwatch);// stop watching 

Callback

function someName(newVal, oldVal, key){
// do whatever
}

Props to watch

You can pass a string

someObject.watch(callback,'name');

You can pass an array

someObject.watch(callback,['name','age']);

You can pass nothing, in which case it will monitor all properties of the object

someObject.watch(callback);

Props to unwatch

Same as above

Usage

vardog={breed: 'pug',name: 'Doug',lastFed: 60}dog.watch(function(newVal,oldVal,key){if(newVal<=0){console.log("I want food again");clearInterval(window.dogFeddInterval);}else{console.log("I'm not hungry yet, I'm going to play with my toys.")}},'lastFed');window.dogFeddInterval=setInterval(function(){dog.lastFed-=10;},10000);