Why is \'this\' Undefined in Vue.js Arrow Functions?
VueJS: Resolving the "this" Undefined Issue
Arrow functions can be a pitfall in VueJS, leading to unexpected undefined values. This is because arrow functions inherit the context of their parent, rather than binding to the Vue instance.
Lifecycle Hooks
When using arrow functions in lifecycle hooks like mounted, this does not refer to the Vue instance. Instead, it refers to the parent context, which is typically an HTML element or the Vue component that triggered the mounted hook.
1 2 3 |
|
Computed Properties
Arrow functions in computed properties also lead to undefined values. As they inherit the parent context, this does not refer to the Vue instance.
1 2 3 4 5 |
|
This results in the error "Uncaught TypeError: Cannot read property 'bar' of undefined".
Solution
To resolve this, use regular functions or ECMAScript 5 function shorthands instead of arrow functions:
1 2 3 |
|
1 2 3 |
|
By using these methods, you can ensure that this always refers to the Vue instance, providing the expected behavior in lifecycle hooks and computed properties.
The above is the detailed content of Why is \'this\' Undefined in Vue.js Arrow Functions?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











Frequently Asked Questions and Solutions for Front-end Thermal Paper Ticket Printing In Front-end Development, Ticket Printing is a common requirement. However, many developers are implementing...

JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.

There is no absolute salary for Python and JavaScript developers, depending on skills and industry needs. 1. Python may be paid more in data science and machine learning. 2. JavaScript has great demand in front-end and full-stack development, and its salary is also considerable. 3. Influencing factors include experience, geographical location, company size and specific skills.

Discussion on the realization of parallax scrolling and element animation effects in this article will explore how to achieve similar to Shiseido official website (https://www.shiseido.co.jp/sb/wonderland/)...

The latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.

How to merge array elements with the same ID into one object in JavaScript? When processing data, we often encounter the need to have the same ID...

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

Explore the implementation of panel drag and drop adjustment function similar to VSCode in the front-end. In front-end development, how to implement VSCode similar to VSCode...
