What does $ mean in js

In JavaScript, the meaning of the "$" symbol

In JavaScript, the "$" symbol is a commonly used selector for selecting DOM elements. It represents the document root element, which is the entire HTML document.

How to use the "$" symbol

To use the "$" symbol to select DOM elements, you can use the following syntax:

<code class="javascript">const element = $(selector);</code>

Where, selector is A CSS selector that specifies the elements to select. For example, to select elements with the "container" class, you would use the following code:

<code class="javascript">const element = $('.container');</code>

Comparison with other selectors

The "$" symbol is often used with other JavaScript selectors, e.g. :

• getElementById(): Select elements based on ID.
• querySelector(): Select the first matching element based on the CSS selector.
• querySelectorAll(): Selects all matching elements based on a CSS selector.

The main advantage of the "$" symbol is that it is shorter and easier to write than other selectors. It also works closely with the jQuery library, a popular DOM manipulation library in JavaScript.

Examples

Here are some examples of selecting DOM elements using the "$" symbol:

• Selecting elements with the "header" class:

<code class="javascript">const header = $('#header');</code>

• Select all paragraph elements:

<code class="javascript">const paragraphs = $('p');</code>

• Select the first button element with class "btn":

<code class="javascript">const button = $('.btn:first');</code>

The above is the detailed content of What does $ mean in js. For more information, please follow other related articles on the PHP Chinese website!