4-Channel Filter Beginner's iOS face test

There are a lot of questions on the Internet for various knowledge points, some people may not really understand the interview and can look very understanding through the back. I summed up the 4 interview questions, a good quick judge whether this person is a qualified engineer, welcome comments.

The difference between 1.struct and class

Before the interview you think all the computer professional students should be able to answer, the fact is that I have more than three of people in the face of the answer.

Sometimes I would also ask what type of array is in swfit and whether there is a performance problem with a large number of copies.

2. Introduce the Observer pattern

Maybe some people already think that the design pattern is a bit outdated, not the whole book read. Even if it's a few design patterns that are commonly used in iOS, I think it's always something to know.

If you say nsnotificationcenter how to use the direct pass.

This answer should consist of three parts: first of all, the design pattern to solve what problems, followed by what solution, and finally is the current system of concrete implementation of the plan.

3. In an HTTPS connected Web site, enter the account password click Login, before the server returned to the request, what happened in the middle

This problem is seen in other, originally the topic is to login to Gmail, but perhaps some people in the country do not know that Google is very early full station HTTPS, so here is particularly pointed out that the connection is HTTPS.

There are a lot of things to talk about here, and there are very many protocols under TCP/IP. There is no need to speak clearly, but the understanding of the entire network connectivity model can be seen in basic skills.

4. In the middle of an app there is a button, after you touch the screen click, to the button to receive click events, what happened in the middle

Runloop and response chains need to be said clearly.

Sometimes you can also ask Uiresponder, Uicontrol, UIView relations.

These 4 problems are just for a quick screening of inappropriate programmers, after all, some people only need a few minutes to know that he is not appropriate, so as to save time.

Lunch at noon I and a senior colleague said these topics, I said, a 15k+ programmer I think I can answer the four questions. He said you are too optimistic, according to the current market he felt afraid to 20k programmer can answer.

4-Channel Filter Beginner's iOS face test