title: Javascript passing object to function
body: <p>Quick question on Javascript to which I can't find a clear concise answer.</p>
  
  <p>I'm building an app that's way ahead of anything I've done before and involves multiple classes being instantiated. These objects are then passed into a processing class that checks user inputs, draws onto canvas and updates the objects that it has been passed.</p>
  
  <p>I am wondering, how does JavaScript handle passing objects to functions? Am I passing a copy of the object, or am I passing a reference to the object?</p>
  
  <p>So if my controller class alters one of the objects variables, is that changed everywhere or just in the object that that controller sees?</p>
  
  <p>Sorry for such a simple, possibly easily testable question but I'm not even sure if I'm making a class correctly at this point thanks to errors piling up.</p>