Thank you for your help. Yes, I've checked all the files, but it looks like I'm missing something. I will try to redo the project again.

I found the cause and fixed it. It turns out that this is a fairly well-known problem that was repeated in previous versions of the Xcode. In my case, I needed to edit the scheme and reload the Xcode. But it only worked when I shifted on another preview, and then returned to the landmarkList preview. The issue has been resolved. The topic is closed.

Thanks a lot!

Thank you so much! It works! P.S. But one question remained with me. Why does Jacob's code work without this? Below is a screenshot of his code.

I used the Interface Bilder

This is my Document Outline on the attached screenshot. I didn't use any code

it is a regular TableViewController with static grouped cells. No code was used here, just an interface builder.

yes it looks like the background of the cell. If I set constraints along with the margins, then the Date Picker will look like this

You know, while we were discussing, I'm already used to this appearance)) I won't dive into the settings, I'll leave it as it is. Thanks a lot for your help! I and other people appreciate it very much!

Thank you so much!

Maybe you need to switch the mode of displaying messages in the console. It is located at the bottom of the Playground. Look at the screenshot below

I think that this should be looked for in some new frameworks

Create your own small applications. For example, currency converter, to-do list, etc.

"How do you deselect?" I use this if condition inside of didSelectRowAt method // Set a checkmark if item.isSelected == false { cell.accessoryType = .checkmark item.isSelected.toggle()// // Remove a checkmark } else { cell.accessoryType = .none item.isSelected.toggle()// } The fact is that in this condition only the first part is executed, and the second part (else) is never executed. And I cannot understand why? "call func reloadROws..." I call tableView.reloadData() but it doesn't work.

Thank you so much! I made a following code:     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {         // Create variable and check it.         guard let cell = tableView.cellForRow(at: indexPath) else { return }          //Clean cell format before select food         cell.accessoryType = .none         // Set checkmark         if foods[indexPath].isSelected == false {             cell.accessoryType = .checkmark             foods[indexPath].isSelected.toggle()         // Remove checkmark         } else {             cell.accessoryType = .none             foods[indexPath].isSelected.toggle()         } LoadSaveData.saveToFile(foods: foods)         tableView.reloadData()     } It works!