After the interview

Today, I’m tired. Today, I’m tired. Today, I’m tired. After the interview in the afternoon, I thought I could finally relax today, but in the evening, I got a phone call to make an appointment for an interview. It was supposed to be a quiet night, and then suddenly a phone call came, another technical interview, and it was from a different department in the same company… At this point I was devastated. Now write down today’s experience with tears……

First phone interview

Project Experience and Practice

This is an unknown A factory that I applied for. When I arrived at the appointed time, the interviewer called me on time. The interviewer is A lovely little sister!! The experience was really good!! But still will ask some more in-depth questions and need to expand the question!! First of all, the process is to introduce yourself and your project experience. I started by telling a lot about my college experience, projects I had done, things I was responsible for, etc. Then the interviewer began to ask questions, actually a lot of problems here are from your resume, ask many questions about your project, what you wrote on the resume, basically will be asked, such as you write the performance optimization, will ask what kind of work did you do, why want to do, and how the actual effect and so on, so must be prepared!

JS & ES6

Then there are some questions about ES6, which are actually started from the project and then expanded to ask what new features you know about ES6. I’m asking the question that the arrow function points to, can I change it? Of course not, the arrow function is integrated with its upper point, which is the arrow function inside this is its external this, there is a lot to learn about this content, especially the various scenarios and various change bindings. There is also a distinction between null and undefined

undefined

  • A declared but undefined variable is used
let a;
console.log(a) // undefined
Copy the code
  • An object attribute is used but does not exist or is not assigned.
let a = {};
console.log(a.b) // undefined
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  • When the function is called, the argument provided does not provide:
const a = (r) => {
    console.log(r);
}
a(); // undefined
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  • If the function returns no value, undefined is returned by default
// const b = a(); console.log(b); //undefinedCopy the code

null

Generally, the following situations occur:

  • Manually assign null to a variable and call that variable
  • Null if you try to get an object and you get nothing

There are some classic problems with null and undefined for example

null == undefined //true
null === undefiend //false! null === ! undefined //true! null == ! undefined //true
typeof undefined // "undefined"
typeof null // "object"
Copy the code

These are the need to understand why the principle, rather than remember the conclusion of the original face still remember to ask the content, now all forget 😂

The browser

Status codes, back-end interactions

My project is using RESTFUL interfaces and requesting this. This is just a general talk about what it does and what it means and how it applies to your project.

The status code returned by the cached resource

Simply speaking, it is the problem of 200 and 304, but this place is extended to a servicWorker, I do not have a very deep understanding of this, so I briefly introduced what this is used for, the rest of the understanding is not too much 😂

React

Pit points in React

I probably went through all the pothole I had, like props and state being mishandled, and infinite rendering being triggered incorrectly.

The life cycle

In terms of performance, there are questions about where to place requests, how to trigger updates when data changes, and where to write this function. Because I was often asked in the project, I answered how I did it, and specifically, I could understand the life cycle.

New features for React16

This is where I cover some of the features of hooks. I then asked about the exact implementation of hooks, and why not use hooks in loops. The hooks implementation is array-based. Do not use hooks in loops or branches because hooks depend on their call order.

And many forgot 😂

engineering

precipitation

Have you done some precipitation of things? Here I just describe the situation in the project. Some components require abstraction and unification.

personnel

Here you see the specific project.

other

Finally, I also asked how familiar I am with Node, because I wrote in my resume that I used Node to do some optimization attempts, and then I gave a general description of my usage and what I used it for. Since I just got in touch with Node, I did not expand it deeply.

The end of the

The whole journey is about more than 70 minutes, round down or feel that some knowledge is lacking, especially the foundation, the foundation is really important, did not know before, did not pay attention to, now crazy repair basic principle. Another is to accumulate practical experience and solutions in multi-point projects, and to be good at thinking. The last point is that the interviewer is really nice!! It’s still very easy to talk through the conversation, so answer whatever you know, but don’t limit yourself to just one aspect. Try to give your answers or solutions from multiple perspectives. Tired tired…. The technical experience of the evening will wait until tomorrow… There’s another one the day after tomorrow…