Understanding Xcode?

Question

iOS

Hello people.
I decided to try myself on the basis of creating applications for iOS.
I got a book on Objective C, I understood the principles of the language, I decided to try to make Hello World.
I more or less figured out Interface Builder, put one label on the form, wrote a greeting to myself, compiled it, sent it to the iPod, everything seems to be as it should be.
Further, according to the plan in the book - interactive, when you click on the button, you need to change the inscription on the label. This is where the stupor came. I can't figure out where to write the code. For example, in the old Turbo Delphi, when double-clicking on a form element, an editor was opened, where all the logic was added. Where is it here? Or at least something similar. They create a class in the book, drag all sorts of things back and forth, in general, it is written in a language that is incomprehensible to me. Explain to me, teapot, what's what, preferably simpler.
Thanks in advance to everyone who will respond.

Answer 1

There are also fresh Stanford lectures on iOS development in iTunes, you should at least listen to them for the sake of the lecturer - an extremely charismatic guy, he explains everything clearly and on his fingers.

Answer 2

You'd better see for yourself. Youtube will teach you quickly.

Answer 3

Apple has a lot of hello worlds in its references, and all of them will always be relevant. To be honest, it's stupid to ask Habr without reading the instructions .
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