search
HomeWeb Front-endJS TutorialHow to understand react

How to understand react

Jan 27, 2021 am 09:26 AM
react

react is a JAVASCRIPT library used to build user interfaces; React is responsible for the presentation of the UI level; the data flow in React flows in one direction from top to bottom along the component tree; React has high performance , the code logic is very simple.

How to understand react

The operating environment of this tutorial: windows7 system, react17.0.1 version, Dell G3 computer.

Related recommendations: "react tutorial"

How to understand react?

As Facebook open sourced React Native for Android , React’s future seems brighter. It has slowly evolved from the earliest UI framework into a set of web application solutions, and the React Native derived from it carries a grand goal: learn once, write anywhere. This seems to be an irresistible attraction for the front end.

React has three keywords:

- Just the ui

- virtual dom

- data flow

To understand React, I start with these three keywords.

2.1 Just the ui

React is responsible for the presentation of the UI level. Although many people use React as the View layer in the [MVC] architecture, this is not the original intention of React.

Under normal circumstances, during the development process, we usually use templates or directly use HTML to build the UI, and HTML is static. Using templates can meet the needs in most cases, but in It seems a bit difficult in complex logical situations. Too many if else or logic controls in the template will make the code difficult to maintain. Of course, this is when a unified template is used in the entire project.

React uses a different approach to solve the problem. It splits the UI into components instead of using a template engine and display logic, making it easy to expand and maintain. Therefore, it introduces the syntax rules of JSX, which allows us to use HTML-like syntax to write js function calls.

2.2 virtual dom

The general process of a browser rendering a page is usually as follows:

Load html->Generate DOM tree->Parse css to generate Render tree- >Generate page

So how does React's virtual dom do it?

Generate virtual dom->diff->Necessary DOM update

Most of the operations are done in js, because we all know that dom operations are very expensive. . So under normal circumstances the performance of React is still very good.

2.3 data flow

The data flow in React flows in one direction from top to bottom along the component tree.

The data flow here refers to the implementation of an application architecture, for example, where the data is stored, where events are triggered, and how to respond to user operations. It is not a new feature provided by React, it should be a practice for building applications with React. After we understand Flux, it may be easier to understand the concept of data flow.

2.4 Flux overview

Flux is an application architecture idea strongly promoted by Facebook's supporting React. It complements React's reusable view components with one-way flow of data.

The same as React’s data flow. In the Flux architecture, data also flows in one direction:

How to understand react

Simply put, all data flows will Pass the Dispatcher. Actions can be generated by action creators and provided to dispatchers, but in most cases actions are generated by user interaction with views.

Capture user interaction at the View layer and generate an Action. By triggering the event callback registered on the Dispatcher, the relevant Store responds to the Action, and then the onChange event on the Store is triggered to further update the View.

Data flow is always one-way as shown in the figure above.

The above is the detailed content of How to understand react. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Is JavaScript Written in C? Examining the EvidenceIs JavaScript Written in C? Examining the EvidenceApr 25, 2025 am 12:15 AM

Yes, the engine core of JavaScript is written in C. 1) The C language provides efficient performance and underlying control, which is suitable for the development of JavaScript engine. 2) Taking the V8 engine as an example, its core is written in C, combining the efficiency and object-oriented characteristics of C. 3) The working principle of the JavaScript engine includes parsing, compiling and execution, and the C language plays a key role in these processes.

JavaScript's Role: Making the Web Interactive and DynamicJavaScript's Role: Making the Web Interactive and DynamicApr 24, 2025 am 12:12 AM

JavaScript is at the heart of modern websites because it enhances the interactivity and dynamicity of web pages. 1) It allows to change content without refreshing the page, 2) manipulate web pages through DOMAPI, 3) support complex interactive effects such as animation and drag-and-drop, 4) optimize performance and best practices to improve user experience.

C   and JavaScript: The Connection ExplainedC and JavaScript: The Connection ExplainedApr 23, 2025 am 12:07 AM

C and JavaScript achieve interoperability through WebAssembly. 1) C code is compiled into WebAssembly module and introduced into JavaScript environment to enhance computing power. 2) In game development, C handles physics engines and graphics rendering, and JavaScript is responsible for game logic and user interface.

From Websites to Apps: The Diverse Applications of JavaScriptFrom Websites to Apps: The Diverse Applications of JavaScriptApr 22, 2025 am 12:02 AM

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python vs. JavaScript: Use Cases and Applications ComparedPython vs. JavaScript: Use Cases and Applications ComparedApr 21, 2025 am 12:01 AM

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

The Role of C/C   in JavaScript Interpreters and CompilersThe Role of C/C in JavaScript Interpreters and CompilersApr 20, 2025 am 12:01 AM

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript in Action: Real-World Examples and ProjectsJavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AM

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

JavaScript and the Web: Core Functionality and Use CasesJavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AM

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.