UITextFieldDelegate Protocol for a UIVewController

Question

I went through this tutorial Your First iPhone Application and it worked great. My question is about the line in the tutorial that reads as follows:

The view controller is also going to be the text field’s delegate; as such, it must adopt the UITextFieldDelegate protocol. To specify that a class adopts a protocol, in the interface add the name of the protocol in angle brackets (<>) after the name of the class from which your class inherits.

If I remove the protocol from view controller the method is still called (message is received) and the keyboard is dismissed. I noticed that all the methods for the UITextFieldDelegate protocol are optional. If that's the case, why declare that the view controller adheres to the protocol? What am I missing? :-)

Answer 1

Because programmers like to keep things organized. Even if all of the methods of a protocol are optional, it's still good form to formally declare that your class implements that protocol if it will be used as a delegate. The delegating class may also require that your class implements the protocol - meaning that if you implement the methods but don't declare that you implement the protocol, you'll get compile warnings.