title: Removing objects in obj-c
body: <p>How I must remove objects?
  For example, I have NSDictionary and some NSStrings from it:</p>
  
  <pre><code>NSDictionary *dict = [NSDictionary dictionaryWithObjects....];
  NSString *str = [dict objectForKey:@"key"];
  </code></pre>
  
  <p><code>[str release];</code> or <code>[str dealloc];</code> or <code>str = nil</code> or it's autorelease object?</p>
  
  <p>If I will remove not autorelease dict, will all child removed too?</p>