Yesterday, in an interview with a recruitment agency, I asked some practical questions. I didn’t do much before, so I was abused. So I would like to ask you some questions:

    1. How to solve the data synchronization of feed stream tableView in news app, for example, the user manually deleted one of the data, and then the data requested by the network is returned, how to achieve data synchronization?

This is my face after the search to the post, you big cow look is this solution is not. Feed stream data synchronization)

    1. Create an instance of class A directly in main. If not, how can I make the instance free when it runs out?

My answer:

First question: Wait until the app process is finished.

Second question: 1. Wrap with autoReleasePool. 2. (It seems that the interviewer is not satisfied with the answer)

    1. What are the major changes to keyWindow in iOS 14.2?

I didn’t pay attention to this, and I don’t know what he wanted to ask. I did a search, but I didn’t find any posts about it. I just found this: iOS 13 gets the keyWindow, and it just mentioned that the way to get the keyWindow has changed since iOS 13

Ps: Finally, I asked how the network layer and data link layer are realized. Although this is the basic knowledge of computer, I felt a little afraid to ask this question from an iOS post.