title: Detect which button is pressed with an UIButton Array
body: <p>I have an UIButton array like this:</p>
  
  <pre><code>@property (nonatomic, retain) IBOutletCollection(UIButton) NSArray *btn_Impact_Collection;
  </code></pre>
  
  <p>and I have this function:</p>
  
  <pre><code>- (IBAction)impactAction:(id)sender;
  </code></pre>
  
  <p>In the XIB file I have nine button, each button is connected to btn_Impact_Collection Array with the Referencing Outlet Collection. Moreover the Touch_inside property of each button is connected to the function ImpactAction.</p>
  
  <p>Now, when a button is clicked the ImpactAction function is called, but inside this function, how can i know which button is pressed?</p>
  
  <p>Thanks in advance for the answer!</p>