Things to note when using v-bind to bind classes in Vue.js
Preface
In Vue.js version: 1.0.27, when using the V-bind instruction in Vue.js to bind class and style, Vue.js has enhanced it. In addition to strings, expression results can also be objects or arrays.
I tested it here and found the following problem:
If you use object syntax to bind a class, the class name must be added with quotation marks, representing the corresponding style, otherwise it will be regarded as an attribute of the object, causing an initialization error.
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="http://cdn.bootcss.com/vue/1.0.27/vue.js"></script>
<style>
.static {
font-size: 120px;
width: 600px;
margin: 0 auto;
background-color: yellow;
height: 120px;
line-height: 120px;
text-align: center;
}
.class-a {
color: #FF0000;
}
.class-b {
text-decoration: underline;
}
</style>
</head>
<body>
<div id="app">
<div v-bind:class="classObject">
关于class的绑定
</div>
</div>
<script>
var vm = new Vue({
el: '#app',
data: {
classObject: {
//'class-a',不能写成class-a（不带引号）；这里的classObject是js对象，而class-b是代表的是一个样式，所以必须写成'class-a',用引号括起来。
//否则这里的class-a只能代表classObject的一个属性名称而已，这样vuejs在初始化时，会报错。
'class-a':false,
'class-b': true
}
}
});
</script>
</body>
</html>Reference materials:
Vue.js official website----http://cn.vuejs.org/guide/class-and-style.html
Supplement:
Here, I feel that the classObject in the code is a bit like a hash table. The key is a style class, and the value is a boolean type value.
Get and change the class-a value in the classObject object from the console, see the picture below:
See the operation in the console, let me I feel that classObject is indeed a bit like a hash table type. In order to confirm this, you can take a look at the source code (ps: I didn’t look at it myself).
In Vue.js1.0.19, the author added some syntax to it. Object syntax can also be used in arrays:
Above, you can add or not add quotes for classA. The following is your own test code.
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="http://cdn.bootcss.com/vue/1.0.27/vue.js"></script>
<style>
.static {
font-size: 120px;
width: 600px;
margin: 0 auto;
background-color: yellow;
height: 120px;
line-height: 120px;
text-align: center;
}
.class-a {
color: #FF0000;
}
.classB {
text-decoration: underline;
}
.classC{
text-shadow: 2px 2px 4px #000000;
}
</style>
</head>
<body>
<div id="app">
<!-- 两种绑定：加引号和不加引号，都可以 -->
<div v-bind:class="[classA, { 'classB': isB, 'classC': isC }]">class绑定</div>
<div v-bind:class="[classA, { classB: isB, classC: isC }]">class绑定</div>
</div>
<script>
var vm = new Vue({
el: '#app',
data: {
classA: 'class-a',
isB: true,
isC: true
}
});
</script>
</body>
</html>Summary
The above is the entire content of this article. I hope the content of this article can bring some help to everyone's study or work. If you have any questions, you can leave a message to communicate.
For more related articles about using v-bind to bind classes in Vue.js, please pay attention to 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
1657
14
1415
52
1309
25
1257
29
1230
24
Demystifying JavaScript: What It Does and Why It Matters
Apr 09, 2025 am 12:07 AM
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.
The Evolution of JavaScript: Current Trends and Future Prospects
Apr 10, 2025 am 09:33 AM
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.
JavaScript Engines: Comparing Implementations
Apr 13, 2025 am 12:05 AM
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.
JavaScript: Exploring the Versatility of a Web Language
Apr 11, 2025 am 12:01 AM
JavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 16, 2025 am 12:12 AM
Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)
Apr 11, 2025 am 08:22 AM
This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base
From C/C to JavaScript: How It All Works
Apr 14, 2025 am 12:05 AM
The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.
How do I install JavaScript?
Apr 05, 2025 am 12:16 AM
JavaScript does not require installation because it is already built into modern browsers. You just need a text editor and a browser to get started. 1) In the browser environment, run it by embedding the HTML file through tags. 2) In the Node.js environment, after downloading and installing Node.js, run the JavaScript file through the command line.
