title: Dot Notation vs Method Notation
body: <p>I'm diving into iOS programming and I'm having difficulty getting my head around the idea of Dot Notation and Method Notation.</p>
  
  <p>As far as I understand it, Dot Notation can be used to invoke setters/getters on properties and is much more cleaner to write/read. Method Notation is used to send messages to objects to manipulate them etc.</p>
  
  <p>Could someone give me a simple explanation as to why the following two statements are essentially different and one will compile but the other will instead fail due to a syntax error.</p>
  
  <pre><code>- (IBAction)digitPressed:(UIButton *)sender 
  {
     NSString *digit = [sender currentTitle];
  
     self.display.text = [self.display.text stringByAppendingFormat:digit];
     self.display.text = self.display.text.stringByAppendingFormat:digit;
  
  }
  </code></pre>
  
  <p>Thanks.</p>