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How to write vue

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2023-05-24 09:48:07613browse

Vue.js is a popular JavaScript front-end framework. Its main purpose is to simplify the complexity in web development and make it easier for developers to build high-performance, scalable web applications. In this article, we will introduce how to write Vue.js.

  1. Preparation

Before you start writing Vue.js, you need to make sure that your development environment has been successfully set up. You'll need basic knowledge of HTML, CSS, and JavaScript, and you'll use Node.js and npm to manage your project dependencies.

Understand the starting code of Vue.js

The starting code of Vue.js is very simple. You only need to include the Vue.js library in the HTML document and then create a Vue instance. The following is a common starting code example: 

<!DOCTYPE html>
<html>
<head>
  <title>Vue.js Example</title>
  <script src="https://cdn.jsdelivr.net/npm/vue"></script>
</head>

<body>
  <div id="app">
    {{ message }}
  </div>

  <script>
    var app = new Vue({
      el: '#app',
      data: {
        message: 'Hello, Vue!'
      }
    })
  </script>
</body>
</html>

Note that the Vue instance here will automatically be bound to the element with the id app. The data property contains the application's state data, in this case a simple message string Hello, Vue!. In HTML templates, use double bracket syntax to output data when referencing the message attribute. This is the template syntax for Vue.js.

  1. Basic concepts

There are some basic concepts in Vue.js that need to be understood. They are:

  • Template syntax: Vue.js uses template syntax to implement data binding and directives, as well as bind events.
  • Instance: An instance of Vue.js is a Vue object, including a data object and related methods.
  • Components: Components are the core part of Vue.js, which can be encapsulated and composed to make applications modular.
  • Custom instructions: Vue.js allows developers to customize instructions to achieve more powerful functions.
  1. Data binding

Data binding in Vue.js is one of its most important features. You can use two-way binding and one-way binding to manage every component and state in your application. In Vue.js, you can use the v-bind directive to bind HTML properties to data in a Vue instance. This is very useful, if you need to update the state of your application, you only need to change the data in the Vue instance and all components that reference that data will automatically update.

Here's an example: 

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

<script>
  var app = new Vue({
    el: '#app',
    data: {
      message: 'Hello, Vue!'
    }
  })
</script>
  1. Directives

Directives in Vue.js are a special syntax for converting an application's State is bound to a view or responds to user events from a view. Instructions start with v-.

Here are some common Vue.js directives:

  • v-if: Display the element if the specified condition is met.
  • v-for: Used to loop through the elements in the rendering list.
  • v-bind: Used to bind HTML attributes to data.
  • v-on: Used to listen to DOM events and respond to them.

Here is an example of using the v-if directive: 

<div id="app">
  <p v-if="isVisible">This is visible if isVisible is true</p>
</div>

<script>
  var app = new Vue({
    el: '#app',
    data: {
      isVisible: true
    }
  })
</script>

In this example, if the isVisible attribute is true, the text in the p tag will be displayed, otherwise the element will be hidden.

  1. Methods

In Vue.js, methods can be instance methods and component methods. In instance methods, you can define functions that handle events. In a component, you can define the methods attribute, which contains the methods used inside the component.

Here is an example: 

<div id="app">
  <button v-on:click="increment">Click me</button>
  {{ counter }}
</div>

<script>
  var app = new Vue({
    el: '#app',
    data: {
      counter: 0
    },
    methods: {
      increment: function () {
        this.counter++;
      }
    }
  })
</script>

In this example, when the user clicks the button, the increment method will increment the value of the counter attribute, and display it on the page.

  1. Components

Components are an important mechanism in Vue.js that can make your web application more modular and flexible. In Vue.js, components can be global or local. A global component can be created using the Vue.component method: 

<script>
  Vue.component('app-header', {
    template: '<h1>This is the app header</h1>'
  })
</script>

You can then use this component in a template: 

<div id="app">
  <app-header></app-header>
</div>

<script>
  var app = new Vue({
    el: '#app',
  })
</script>

In this example, when Vue.js When parsing the template, it looks for the app-header tag and generates a new component.

  1. Summary

In this article, we covered how to create a web application using Vue.js. We discussed the main features and mechanisms of Vue.js from the aspects of getting started, basic concepts, data binding, directives, methods and components. The flexibility and ease of use of Vue.js have made it a very popular front-end framework and tool. We believe that with a deep understanding of these concepts and techniques, you can more easily write useful Vue.js applications.

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JavaScript node.js css vue.js html npm 前端框架 if for 封装 字符串 循环 JS 对象 事件 dom
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