Home Web Front-end Front-end Q&A Some thoughts on React this binding

Some thoughts on React this binding

Jun 11, 2018 pm 10:23 PM

When we develop react projects, we usually encounter this binding problems. The solution methods are summarized into the following three situations:

import React from 'react'export default class Demo extends React.Component{
    constructor(props){        super(props);        this.click1.bind(this)//方式1: 在构造函数内绑定
    }
    click1(){
    }
    click2=()=>{//方式2: 使用箭头函数
    }
    click3(){
    }
    render(){        //方式3: 在render内绑定
        return <p>
            <button onClick={this.click2}></button>
            <button onClick={this.click3.bind(this)}></button>
        </p>
    }
}
Copy after login

All three methods can achieve the same effect, but there is still a big difference in performance.

First of all, the third method has the worst performance. You have to bind this every time you render.

For the second and third types, we can’t actually see the difference when we look at it this way, but if we compile the code to ES5, we can see the difference:

Some thoughts on React this binding

First, use the arrow function method, which is actually defined on this, that is, in each instantiation This method will be defined in this later, but through method 1, this method is actually defined on prototype, and each instance object shares this method. Therefore, purely from the perspective of memory space consumption, method 1 is actually the best.

But for a method defined on the prototype chain, when the method is actually called, the search process is as follows:
First check whether there is a definition of the method on this , if not, go to prototype to find out whether the method exists, so during the method call, you will go through a cross-prototype chain search. This process is the additional consumption caused by method 1.

But the arrow function method, when actually called, accesses _this of the outer function cache, so there is a layer of consumption in scope search.

After private testing, we found that the performance of searching on the prototype chain is much better than searching on the scope. So overall, the second method is the best.

In addition, looking at the foreigner's code, I found a batch binding method, which is actually an optimization of the first solution. You can simply learn from it:
Some thoughts on React this binding

Some thoughts on React this binding

This article explains some thoughts on React this binding. For more related content, please pay attention to the php Chinese website.

Related recommendations:

The problem of passing values ​​​​from the parent component to the child component echarts in vue

Javascript strict mode detailed explanation

Related code analysis of php to implement login function

The above is the detailed content of Some thoughts on React this binding. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
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

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

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1657
14
PHP Tutorial
1257
29
C# Tutorial
1230
24
React's Role in HTML: Enhancing User Experience React's Role in HTML: Enhancing User Experience Apr 09, 2025 am 12:11 AM

React combines JSX and HTML to improve user experience. 1) JSX embeds HTML to make development more intuitive. 2) The virtual DOM mechanism optimizes performance and reduces DOM operations. 3) Component-based management UI to improve maintainability. 4) State management and event processing enhance interactivity.

React and the Frontend: Building Interactive Experiences React and the Frontend: Building Interactive Experiences Apr 11, 2025 am 12:02 AM

React is the preferred tool for building interactive front-end experiences. 1) React simplifies UI development through componentization and virtual DOM. 2) Components are divided into function components and class components. Function components are simpler and class components provide more life cycle methods. 3) The working principle of React relies on virtual DOM and reconciliation algorithm to improve performance. 4) State management uses useState or this.state, and life cycle methods such as componentDidMount are used for specific logic. 5) Basic usage includes creating components and managing state, and advanced usage involves custom hooks and performance optimization. 6) Common errors include improper status updates and performance issues, debugging skills include using ReactDevTools and Excellent

React Components: Creating Reusable Elements in HTML React Components: Creating Reusable Elements in HTML Apr 08, 2025 pm 05:53 PM

React components can be defined by functions or classes, encapsulating UI logic and accepting input data through props. 1) Define components: Use functions or classes to return React elements. 2) Rendering component: React calls render method or executes function component. 3) Multiplexing components: pass data through props to build a complex UI. The lifecycle approach of components allows logic to be executed at different stages, improving development efficiency and code maintainability.

Frontend Development with React: Advantages and Techniques Frontend Development with React: Advantages and Techniques Apr 17, 2025 am 12:25 AM

The advantages of React are its flexibility and efficiency, which are reflected in: 1) Component-based design improves code reusability; 2) Virtual DOM technology optimizes performance, especially when handling large amounts of data updates; 3) The rich ecosystem provides a large number of third-party libraries and tools. By understanding how React works and uses examples, you can master its core concepts and best practices to build an efficient, maintainable user interface.

React's Ecosystem: Libraries, Tools, and Best Practices React's Ecosystem: Libraries, Tools, and Best Practices Apr 18, 2025 am 12:23 AM

The React ecosystem includes state management libraries (such as Redux), routing libraries (such as ReactRouter), UI component libraries (such as Material-UI), testing tools (such as Jest), and building tools (such as Webpack). These tools work together to help developers develop and maintain applications efficiently, improve code quality and development efficiency.

React: The Power of a JavaScript Library for Web Development React: The Power of a JavaScript Library for Web Development Apr 18, 2025 am 12:25 AM

React is a JavaScript library developed by Meta for building user interfaces, with its core being component development and virtual DOM technology. 1. Component and state management: React manages state through components (functions or classes) and Hooks (such as useState), improving code reusability and maintenance. 2. Virtual DOM and performance optimization: Through virtual DOM, React efficiently updates the real DOM to improve performance. 3. Life cycle and Hooks: Hooks (such as useEffect) allow function components to manage life cycles and perform side-effect operations. 4. Usage example: From basic HelloWorld components to advanced global state management (useContext and

The Future of React: Trends and Innovations in Web Development The Future of React: Trends and Innovations in Web Development Apr 19, 2025 am 12:22 AM

React's future will focus on the ultimate in component development, performance optimization and deep integration with other technology stacks. 1) React will further simplify the creation and management of components and promote the ultimate in component development. 2) Performance optimization will become the focus, especially in large applications. 3) React will be deeply integrated with technologies such as GraphQL and TypeScript to improve the development experience.

React vs. Backend Frameworks: A Comparison React vs. Backend Frameworks: A Comparison Apr 13, 2025 am 12:06 AM

React is a front-end framework for building user interfaces; a back-end framework is used to build server-side applications. React provides componentized and efficient UI updates, and the backend framework provides a complete backend service solution. When choosing a technology stack, project requirements, team skills, and scalability should be considered.

See all articles