I watched the videos twice already, and I am taking a break to redo iExpense and really metabolise how it works. What I really don't get is why we're creating 2 extra files, one with a struct and one with a class.

I understand the class is made to define a new type of variable, Expenses, but why do we need the ExpenseItem.swift file with a struct defining expenses, instead of having it all in the class?

Please explain to me as the newbie I am. No simplification will be too simple for me 😉

Thank you @ygeras ! That's exactly what I wanted to understand.

From architecture point of view, meaning why they are created in different files, this is for convenience purpose. You can just put the class and the struct in ContentView file as well, and nothing will change. As your project grows it will become more difficult to search for necessary parts of the code etc. So it makes sense to separate those parts in different files so that you can navigate easily.

This makes complete sense, since I have already started hating having to scroll up and down to find things.

Basically in this project Expenses Class is your LogBook object, and you have one logbook, so you can reference to it in your app. And ExpenseItem struct is single entry in your logbook but you will have many of them.

And this is exactly what I was trying to understand! So basically, I define what a single entry will look like with a struct, and reference it in a class as if the class was a binder and each entry (the struct) a sheet I can slot in, which is why it's an array. Thank you SO much for this!