title: Xcode: "Build and run" without restarting iPhone emulator
body: <p>I just started fighting my way to Xcode and iPhone development, so this is probably a stupid question, but there is this strange behavior of Xcode that I can't seem to get behind.</p>
  
  <p>When I change my code (.m, .h files) and press "Build and Run", the (already running) emulator seems to restart my app, but doesn't actually reflect my changes.</p>
  
  <p>On the other hand, if I modify the UI (the .xib files), I do see the changes after "Build and Run". </p>
  
  <p>The only way to test the code changes seems to be to manually exit the emulator and restart, which I grow tired of very quickly.</p>
  
  <p>There must be something I'm missing. What is it?</p>