In-depth analysis of Vue selectors: Master common Vue selectors

Detailed explanation of Vue selectors: Master the commonly used selectors in Vue

Introduction: Vue.js is a lightweight JavaScript framework that is used in front-end development Widely used. Vue provides a rich set of selectors to select and manipulate DOM elements. This article will introduce in detail the commonly used selectors in Vue to help readers better master Vue's selector functions.

1. Overview of selectors

1.1 What is a selector

A selector is a tool used to select and manipulate DOM elements. In Vue, selectors play the role of finding and manipulating elements in HTML.

1.2 Selector classification

Vue selectors can be divided into two categories: basic selectors and advanced selectors.

Basic selectors include element selectors, class selectors, ID selectors and attribute selectors. The element selector selects elements by tag name, the class selector selects elements by class name, the ID selector selects elements by the element's unique ID, and the attribute selector selects elements by the element's attribute value.

Advanced selectors include descendant selectors, child element selectors, adjacent sibling selectors and universal selectors. The descendant selector selects the descendant elements of an element, the child element selector selects the direct child elements of an element, the adjacent sibling selector selects the immediate sibling elements of an element, and the universal selector selects all elements.

2. Commonly used Vue selectors

2.1 Element selector

The element selector is the most basic selector in Vue. It selects elements through their tag names. . For example, you can use the element selector to select all p elements on the page:

<p>这是一个段落</p>
<p>这也是一个段落</p>

var element = document.querySelector('p');
console.log(element); // 输出：<p>这是一个段落</p>

2.2 Class selector

The class selector selects elements through the element's class attribute value. In Vue, you can use class selectors to set styles or perform other operations on specific elements. For example, you can use the class selector to select all elements with class "red":

<div class="red">红色的div</div>
<div>蓝色的div</div>

var elements = document.querySelectorAll('.red');
console.log(elements); // 输出：[<div class="red">红色的div</div>]

2.3 ID selector

The ID selector selects elements through the element's id attribute value. ID selectors in Vue are similar to class selectors, but ID selectors can only select elements on the page that have a unique ID. For example, you can use the ID selector to select the element with the id "main":

<div id="main">主要内容</div>
<div>辅助内容</div>

var element = document.querySelector('#main');
console.log(element); // 输出：<div id="main">主要内容</div>

2.4 Attribute Selector

The attribute selector selects elements by their attribute values. Attribute selectors in Vue can select elements based on their attribute values. For example, you can use the attribute selector to select all elements with the data-type attribute "html":

<div data-type="html">HTML元素</div>
<div>其他元素</div>

var elements = document.querySelectorAll('[data-type="html"]');
console.log(elements); // 输出：[<div data-type="html">HTML元素</div>]

2.5 Descendant selector

The descendant selector selects the descendant elements of an element. In Vue, you can use the descendant selector to select all descendant elements under an element. For example, you can use the descendant selector to select all p elements under the element with the id "container":

<div id="container">
  <p>第一个段落</p>
  <div>
    <p>第二个段落</p>
  </div>
</div>

var elements = document.querySelectorAll('#container p');
console.log(elements); // 输出：[<p>第一个段落</p>, <p>第二个段落</p>]

2.6 Child element selector

The child element selector selects the direct children of an element element. In Vue, you can use the child selector to select all direct children of an element. For example, you can use the child element selector to select all direct child elements of the element with the id "container":

<div id="container">
  <p>第一个段落</p>
  <div>
    <p>第二个段落</p>
  </div>
</div>

var elements = document.querySelectorAll('#container > *');
console.log(elements); // 输出：[<p>第一个段落</p>, <div><p>第二个段落</p></div>]

2.7 Adjacent sibling selector

The adjacent sibling selector selects an element 's immediate sibling element. In Vue, you can use the adjacent sibling selector to select the immediate sibling elements of an element. For example, you can use the adjacent sibling selector to select the immediate sibling elements of the element with the id "container":

<div id="container">第一个div</div>
<div>紧邻的兄弟div</div>
<div>其他div</div>

var element = document.querySelector('#container + div');
console.log(element); // 输出：<div>紧邻的兄弟div</div>

2.8 Universal Selector

The universal selector selects all elements. In Vue, you can use universal selectors to select all elements on the page. For example, you can use a universal selector to select all elements on the page:

<p>这是一个段落</p>
<div>这是一个div</div>
<span>这是一个span</span>

var elements = document.querySelectorAll('*');
console.log(elements); // 输出：[<p>这是一个段落</p>, <div>这是一个div</div>, <span>这是一个span</span>]

Conclusion: Vue selectors are a very important part of Vue.js. Mastering Vue selectors can help developers better operate and control DOM element. Through the introduction of this article, readers can understand the commonly used selector types and usage methods in Vue, so as to better apply Vue selectors for front-end development. Hope this article can be helpful to readers.

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