title: AngularJS - Why have more than one controller
body: <p>What reasons are there to have multiple controllers in an AngularJS application? I've built a few angular apps now and I've never encountered a problem where I thought multiple controllers would make things easier for me.</p>
  
  <p>I'm still a bit of a n00b, have never written a unit test and my code isn't as manageable as it could be so I'm sure it's just ignorance. And I've heard that other people have multiple controllers.</p>
  
  <p>Put another way: how does one know that they should create a new controller?</p>