How to find elements in js

The methods to find elements in JavaScript are: getElementById(id): Use the element ID to find the element. getElementsByClassName(className): Find elements using class names. getElementsByTagName(tagName): Find elements using tag names. querySelectorAll(selector): Find elements using CSS selectors. querySelector(selector): Use a CSS selector to find the first matching element.

Methods to find elements in JavaScript

In JavaScript, there are the following common methods for finding elements ：

1. getElementById(id):
Find the element using its unique ID attribute. It returns the first element with the specified ID.

Example:

<code class="javascript">const element = document.getElementById('myElement');</code>

2. getElementsByClassName(className):
Find an element using its class name attribute. It returns a collection of all elements with the specified class name.

Example:

<code class="javascript">const elements = document.getElementsByClassName('myClass');</code>

3. getElementsByTagName(tagName):
Find elements using HTML tag names. It returns a collection of all elements with the specified tag.

Example:

<code class="javascript">const elements = document.getElementsByTagName('p');</code>

4. querySelectorAll(selector):
A general search method that uses CSS selectors to select from documents Find elements in . It returns a collection of all elements matching the selector.

Example:

<code class="javascript">const elements = document.querySelectorAll('.myClass p'); // 选择带有 myClass 类名的段落</code>

5. querySelector(selector):
Similar to querySelectorAll, but it only returns those that match the selector The first element.

Example:

<code class="javascript">const element = document.querySelector('.myClass');</code>

Other methods:

• document.forms: Get Form collection.
• document.images: Get the image collection.
• document.links: Get the link collection.

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