Record some questions that you did not answer well during the interview

After being abused by an interview, I found that I didn’t know enough about some issues, or I knew how to use it, but I couldn’t say it. I clearly couldn’t explain the ideas/processes of the project I wrote, and there was inheritance that I just gave up to understand before. /Deep into the principles and so on, I will try my best to organize and record them when I think about it in the future

1. are some practical scenarios in 1610c9a7f5fa9e work that can use closures?

   • closure : a function and its surrounding state (lexical environment, lexical environment) reference is bundled together-from MDN (lexical environment: according to the location of this variable to determine where it can be used)
   • solved by 1610c9a7f5fafc/purpose of use : Use function external data inside the function to solve the problem that js does not have private variables
   • Return to the topic : Closures can be used wherever private variables are needed. For example, the implementation of the anti-shake throttling function uses closures, as well as the development of plug-ins, etc., and the application scenarios are very wide.

   • Thinking Expansion : When I looked at the function currying before, I was in a state of a little understanding, so I will reorganize it here.

     • Realization of fixed parameters (use closures directly, and multiple parameters can be written infinitely below function):
       
     • But in actual use, the parameters are often not fixed, and the realization of not fixed parameters:
       
     • You have to call an empty one, which seems a bit strange (I saw that other people’s implementations used toString before, but I’m not sure why toString can determine whether to return the result? So I tried it myself, and toString really doesn’t work unless you manually give the function to the function. Wrap a layer of String..., you can try here
       
     • Ah, the first question has been written for a long time. When I checked the information, I saw the animations of other people’s blogs. It was so interesting... Then... I ran off the track... ORZ

2. The difference between Axios and Ajax?

   • Ajax is a package based on XHR and relies on JQuery
   • Axios is also based on XHR packaging, but it is implemented using Promise
   • Axios is more convenient and does not depend on any framework

3. How does Asyc Await perform error interception?

   • try/catch

4. asynchronous development process?

   • Callback (event callback/AJAX) (callback hell)
   • Promise (commonly used)
   • Generator/yield (difficult to understand)
   • Async/Await

5. is the usage scenario and implementation principle of $nextTick in 1610c9a7f5fdfa VUE?

   • A callback executed after the dom update is complete
   • Implementation principle: TODO

6. inheritance and prototype chain

   • The difference between prototype and __proto__

     • __proto__ points to prototype
     • After each object is created, there will be a __proto__
     • prototype is a built-in property of the function
     • __proto__ is a built-in property of the object
   • All js objects are instances of Object, inheriting the properties and methods of Object.prototype
   • Implement an inheritance // TODO
7. implements a simple two-way binding (just use defineProperty)
   
8. Anti-shake/throttle (I wrote this out! But because it is a high frequency problem, please also record it~)
   

...To be continued

... please correct me