15 aspects of the analysis of the front end of the test, good guy finishing directly want to and dachang line

preface

It is really 15 aspects of the front end of the exam, the answers to the questions are in the document, only part of the questions are listed for length reasons, the full version can beCheck it out here.

Summary of the front-end knowledge

HTML/CSS

Understanding of Web fidelity (structure/presentation/behavior), browser kernel, rendering principles, dependency management, compatibility, CSS syntax, hierarchy, common properties, Layout, selector, box model, Hack, CSS preprocessor, Flexbox, CSS Modules, Document Flow, BFC, HTML5 (Offline & Storage & History, Multimedia, webGL, SVG, Cavas)

Javascript

Data types, operations, objects, inheritance, closures, scopes, events, Prototype, RegExp, JAON, Ajax, DOM, memory leaks, Cross-domain, asynchronous requests, template engines, modularity, Flux, isomorphism, Algorithms, Nodejs, HTTP

other

Mainstream MVVM, Hybrid App\React Native\Weex, TypeScript, front-end engineering, dependency management, performance optimization, refactoring, SEO, UED, front-end technology selection, etc

Master the front end questions

HTML

What does Doctype do?
The difference between standard and weird modes:
What are inline elements/block-level elements/empty elements?
What is your understanding of the browser kernel?
What are the kernels of common browsers?
How do browsers manage and load HTML5 offline storage resources?
Describe the difference between cookies/sessionStorage and localStorage?
What are the new HTML5 features? How to deal with the compatibility of HTML5’s new tags? How to distinguish HTML from HTML5?
What is your understanding of HTML semantics?
How to use HTML5 offline cache? Can you explain how it works?

CSS

☆ Browser box model?
☆ Clear floating mode
What are the CSS selectors? Which attributes can be inherited?
The difference between ::after/:after and ::before/:before?
CSS style priority calculation method:
☆ What are the new CSS3 features and pseudo-classes?
Some advantages of less.
How do I center div?
What are the values of Display? Explain their role
The value of the Position?
Flex layout and common properties
Please explain the FLExbox (flexible box layout model) of CSS3 and how it works?
CSS triangles?
Full screen font layout?
What is the cause of the invisible gap between Li and Li?
Why do I initialize CSS styles?
CSS visibility property collapse[kə’læps] property
What does margin merge mean?

JS

What are the JS data types?
What built-in objects does JS have?
What’s the difference between stack and heap?
Scope and variable declaration enhancement in JS
How to convert a type?
What are object-oriented programming and procedural programming, their similarities and differences, their strengths and weaknesses
Object-oriented programming ideas
How to explain the role of this in JS?
Js with this (classic) :
☆ Talk about JS prototypes and prototype chains
How to determine exactly if a variable is an array type?
☆ What is the difference between call and apply?
What are the methods of inheritance?
☆ What is a closure? What do closures do?
Event Agent (event delegate) :
The stages of the event
What stages does the ☆new operator go through when creating an instance
The implementation of asynchronous programming
Knowledge of native JS
What are the methods of lazy loading of JS?
Sort the array from smallest to largest?
The reverse() method is added to reverse the order of the array

JQuery:

What do you think is good about jQuery or Zepto source code
How does jQuery work?
What object is returned by the init method of jquery.fn? Why return this?
What is the difference between jquery.extend and jquery.fn.extend?
What is the principle of jQuery property copy (extend), how to achieve deep copy?
How are JQuery queues implemented? Where can queues be used?
Bind (), live (), delegate (), and on () in jQuery
How is it possible to bind multiple events to a jQuery object at the same time?
Optimization for jQuery?

Data request related issues

What are the HTTP request methods?
What are the HTTP status codes? Let me tell you what they mean
Describe the difference between GET and POST
Error in the length of get request parameters
Cache differences between GET and POST requests
What is the difference between HTTP and HTTPS? How to use it flexibly?
AJax is what? Why Ajax?
Briefly describe the ajax process.
Pros and cons of Ajax?
XMLHttpRequest Generic properties and methods
How many times do Ajax requests cross domain interfaces get sent?
Several ways to cross domains
How can a Web application actively push the Data client from the server?
How to implement communication between multiple tabs in the browser? (ali)
How does webSocket work with low browsers? (ali)
Detailed differences and pros and cons between FETCH, Ajax, axiOS:
What is Axios? How to use it? Describe the process of using it to implement the login function?
The difference between XML and JSON?

Vue

What is the MVVM?
The difference between MVVM and MVC? How does it differ from other frameworks (JQuery)? Which scenarios fit?
What are the two cores of vue.js?
Value transfer between Vue components
How to use custom components in VUE-CLI, and what are the problems encountered?
How does Vue implement load on demand with Webpack setup
Similarities and differences between V-show and V-IF directives
How do I make CSS work only in the current component
What is the function of?
Talk about keep-alive implementation principles and caching strategies
Steps to introduce components in Vue
Vue common modifiers?
What are the calculated properties of Vue?
What are the advantages and disadvantages of single-page applications like Vue?
What does the instruction V-EL do?
Steps for using plug-ins in Vue
Active-class is a property of which component?
Name at least 4 vUE directives and their usage.

React

React props and state
How do react components communicate with each other?
Why does the virtual DOM improve performance?
React lifecycle function:
React performance optimization is what periodic function?
At what point in the lifecycle should you make an AJAX request?
Give an overview of the event handling logic in REact
How do I tell React that it should build the production version?
What happens after setState is called?
React setState
Why is setState asynchronous?
What does the second argument passed to the setState function do?
What is shouldComponentUpdate for and why is it important?
What is the difference between createElement and cloneElement?
Why do we need to use the Children API provided by React instead of JS map?
What’s the difference between Element and Component in React?
When would you prefer to use Class Component over Functional Compone
What does refs do in React?
The diff algorithm?

Wechat applets

Brief description of wechat small program related file types?
How do you encapsulate the data request of wechat applets?
What are the methods for passing parameters?
What methods have you used to improve the application speed of wechat mini program?
Which is better, small program or native App?
Brief introduction to the principle of wechat applets?
Analyze the advantages and disadvantages of wechat applets
Micro channel small program and H5 difference?
How to solve the small program asynchronous request problem?
How is bidirectional binding of applets different from vUE
What are the differences between WXSS and CSS for applets?
How to determine the uniqueness of the user associated with the small program wechat public number?
What should I pay attention to when using webView direct loading?
What problems do applets encounter when calling background interfaces?
Applets writing custom components, what to consider?
How does applets get user authorization information?
Add a button button to the page and set the open-type property to getUserInfo.
How do applets share card information?

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