title: arc, strong and weak instance variables
body: <p>Just trying to fully understand ARC.</p>
  
  <pre><code>MyView *testView = [[MyView alloc] init];
  
  __weak MyView *weakView = testView;
  
  [weakView addObserver:self forKeyPath:@"alpha" options:0 context:nil];
  
  testView = nil;
  
  if(weakView) {
       NSLog(@"WeakView exists!");
  }
  </code></pre>
  
  <p>I don't understand why my NSLog statement is printing. Since weakView is a weak reference to testView, shouldn't it be pointing to nil once testView is set to nil???</p>
  
  <p>Thanks!</p>