Summary of commonly used instructions in Vue-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

Summary of commonly used instructions in Vue

不言

Jul 26, 2018 pm 12:53 PM

The content shared with you in this article is a summary of commonly used instructions in Vue. The content is very detailed. Next, let’s take a look at the specific content. I hope it can help friends in need.

1 Commonly used commands

v-if command
v-show command
v-else instruction
v-for instruction
v-bind instruction
v-model
v-on command
v-text command

1.1 v-if is a conditional rendering instruction, which deletes and inserts elements based on the true or false expression. Its basic syntax is as follows:

v-if="expression"

expression is an expression that returns a bool value. Expression The formula can be a bool attribute or an operation formula that returns bool. For example:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <script type="text/javascript" src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
    </head>
    <body>
        <div id="app">
            <h1 id="Hello-nbsp-Vue-js">Hello, Vue.js!</h1>
            <h1 id="Yes">Yes!</h1>
            <h1 id="No">No!</h1>
            <h1 id="nbsp-Age-nbsp-nbsp-age-nbsp">= 25">Age: {{ age }}</h1>
            <h1 id="nbsp-Name-nbsp-nbsp-name-nbsp">= 0">Name: {{ name }}</h1>
        </div>
    </body>
    <script src="js/vue.js"></script>
    <script>
        
        var vm = new Vue({
            el: &#39;#app&#39;,
            data: {
                yes: true,
                no: false,
                age: 28,
                name: &#39;keepfool&#39;
            }
        })
    </script>
</html>

The display result is as follows,

Note: v-if instruction is executed based on the value of the conditional expressionInsertion or deletion behavior of elements.

1.2 v-for directive

v-for directive renders a list based on an array, which is similar to JavaScript’s traversal syntax :

v-for="item in items"

items is an array, item is the array element currently being traversed.

Sample code:


    
        
            
                
                    name
                    age
                

            
            
                
                     {{item.name}}
                     {{item.age}}

name	age
{{item.name}}	{{item.age}}

1.3 The v-bind directive can take a parameter after its name, separated by a colon. This parameter is usually an attribute of the HTML element, for example ：v-bind:class

v-bind:argument="expression"

1.4 v-model

v-model (value, checked, and selected will be ignored after the form element is set), commonly used in Forms and

allow form elements and data to achieve two-way binding (mapping relationship)

Sample code

<p id="app">
    <p v-text="message"> </p>
    <input type="text" v-model="message">
</p>

</body>

<script type="text/javascript">    var app = new Vue({
        el:"#app",
        data:{
            message:"nice to meet you"
        }
    })</script>

1.5 The v-on directive is used to monitor DOM events. Its syntax is similar to v-bind. For example, to monitor the click event of the element:

<a v-on:click="doSomething">

There are two forms of calling methods:Bind a method (let the event point to a reference to the method), or use an inline statement.
The Greet button binds its click event directly to the greet() method, while the Hi button calls the say() method.

It is a very common requirement to call event.preventDefault() or event.stopPropagation() in an event handler. Vue.js provides event modifiers for v-on. As mentioned before, modifiers are represented by instruction suffixes starting with a dot.

.stop
.prevent
.capture
.self
.once
.passive

<!-- 阻止单击事件继续传播 -->
<a v-on:click.stop="doThis"></a>

<!-- 提交事件不再重载页面 -->
<form v-on:submit.prevent="onSubmit"></form>

<!-- 修饰符可以串联 -->
<a v-on:click.stop.prevent="doThat"></a>

<!-- 只有修饰符 -->
<form v-on:submit.prevent></form>

<!-- 添加事件监听器时使用事件捕获模式 -->
<!-- 即元素自身触发的事件先在此处处理，然后才交由内部元素进行处理 -->
<p v-on:click.capture="doThis">...</p>

<!-- 只当在 event.target 是当前元素自身时触发处理函数 -->
<!-- 即事件不是从内部元素触发的 -->
<p v-on:click.self="doThat">...</p>

Vue.js is the two most commonly used instructions v-bind and v-on provides an abbreviation. The v-bind instruction can be abbreviated to a colon, and the v-on instruction can be abbreviated to the @ symbol.

<!--完整语法-->
<a href="javascripit:void(0)" v-bind:class="activeNumber === n + 1 ? &#39;active&#39; : &#39;&#39;">{{ n + 1 }}</a>
<!--缩写语法-->
<a href="javascripit:void(0)" :class="activeNumber=== n + 1 ? &#39;active&#39; : &#39;&#39;">{{ n + 1 }}</a>

<!--完整语法-->
<button v-on:click="greet">Greet</button>
<!--缩写语法-->
<button @click="greet">Greet</button>

1.6 The v-text directive is mainly to prevent {{}} from appearing on the page when the page is first loaded

v-text="expresstion"

Related recommendations:

ECMAScript Usage examples of typeof in

How does vue.js implement tree table encapsulation? How to implement tree table in vue.js

The above is the detailed content of Summary of commonly used instructions in Vue. 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

Behind the Scenes: What Language Powers JavaScript?Apr 28, 2025 am 12:01 AM

JavaScript runs in browsers and Node.js environments and relies on the JavaScript engine to parse and execute code. 1) Generate abstract syntax tree (AST) in the parsing stage; 2) convert AST into bytecode or machine code in the compilation stage; 3) execute the compiled code in the execution stage.

The Future of Python and JavaScript: Trends and PredictionsApr 27, 2025 am 12:21 AM

The future trends of Python and JavaScript include: 1. Python will consolidate its position in the fields of scientific computing and AI, 2. JavaScript will promote the development of web technology, 3. Cross-platform development will become a hot topic, and 4. Performance optimization will be the focus. Both will continue to expand application scenarios in their respective fields and make more breakthroughs in performance.

Python vs. JavaScript: Development Environments and ToolsApr 26, 2025 am 12:09 AM

Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.

Is 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 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 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 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 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.

See all articles

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

Assassin's Creed Shadows: Seashell Riddle Solution

1 months agoByDDD

What's New in Windows 11 KB5054979 & How to Fix Update Issues

3 weeks agoByDDD

Where to find the Crane Control Keycard in Atomfall

1 months agoByDDD

How to fix KB5055523 fails to install in Windows 11?

2 weeks agoByDDD

InZoi: How To Apply To School And University

3 weeks agoByDDD

Hot Tools

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),