title: How to set the titleLabel.text of a UIButton?
body: <p>I would like to know how to do that properly because I am getting a Bad Access error.</p>
  
  <p>In my app I have 81 <code>UIButtons</code> with an <code>IBAction</code> attached to all of them by Interface Builder, this <code>IBAction</code> should set the text of the button the user tapped on. I am trying to do that this way:</p>
  
  <pre><code>- (IBAction)changeTitle:(UIButton *)button {
      button.titleLabel.text = [NSString stringWithFormat:@"%@", myString];
  }
  
  -(IBAction)setMyString:(id)sender{
  myString = [NSString stringWithFormat:@"text"];
  }
  </code></pre>
  
  <p>However this comes into a Bad Access Error, how could I solve that?
  Million Thanks!</p>
  
  <p>error message: EXC_BAD_ACCESS (code=1, address=0x0)
  (lldb)</p>