Can I add a property dynamically in javascript?
<p>Is it okay to add properties to an object at runtime? It seems to run okay but are there any issues I should be aware of?</p>

<p>I'm using a 3rd party javascript API which has an object class, which I've instantiated and added my own property to after instantiation,  like the code below:</p>

<p>For example can I do this:</p>

<pre><code>var Car = function (id, type) {
    this.id = id;
    this.type = type;
};

var myCar = new Car(1,"Nissan");

// CAN I DO THIS: (needsWork not a property of object Car)
myCar.needsWork = true;
</code></pre>
