Table of Contents
Using the Node.contains() method
Example
Use hasChildNodes() method
Home Web Front-end JS Tutorial How to return true in JavaScript if parent element contains child elements?

How to return true in JavaScript if parent element contains child elements?

Sep 03, 2023 pm 09:01 PM

如果父元素包含子元素,JavaScript 中如何返回 true?

In this tutorial, we will learn how to return true if the parent element contains a child element in JavaScript. Suppose you have two HTML elements, a parent element and a child element, and you want to know if the parent element contains the child element.

Using the Node.contains() method

The contains() method of the Node interface returns a Boolean value indicating whether the node is a descendant of the given node.

If you want to know whether the parent node is an element that contains child elements, you can use the Node.contains() method.

This is a simple example -

<div id="parent">
   <p id="child">Some text</p>
</div>
Copy after login
Copy after login

The JavaScript code snippet below checks if a parent element contains a child element.

var parent = document.getElementById("parent");
var child = document.getElementById("child");

document.getElementById("result").innerHTML = parent.contains(child) 
// returns true
Copy after login

In the above code, we use the getElementById() method to get references to parent and child elements.

Then we use parent.contains(child) to check whether the parent element contains child elements.

Example

Here is the complete HTML code -

<html>
<head>
   <title>Examples</title>
</head>
<body>
   <div id="parent">
      <p id="child"></p>
   </div>
   <div id="result"></div>
   <script>
      var parent = document.getElementById("parent");
      var child = document.getElementById("child");
      document.getElementById("result").innerHTML ="Does parent contain child: "+ parent.contains(child)
   </script>
</body>
</html>
Copy after login

Use hasChildNodes() method

Another way to check if the parent element contains any child elements The method is to use the hasChildNodes() method.

Returns true if the hasChildNodes() method contains any child elements.

This is a simple example-

<div id="parent">
   <p id="child">Some text</p>
</div>
Copy after login
Copy after login

See the JavaScript code below-

var parent = document.getElementById("parent");
var child = document.getElementById("child");

document.getElementById("result").innerHTML = parent.hasChildNoodes();
Copy after login

In the above code, we use the getElementById() method to get the parent element and child A reference to the element.

Then we use the hasChildNodes method to check whether the parent element exists and whether the element has child elements.

Example

Here is the complete HTML code -

<!doctype html>
<html>
<head>
   <title>Examples</title>
</head>
<body>
   <div id="result"></div>
   <div id="parent">
      <p id="child"></p>
   </div>
   <script>
      var parent = document.getElementById("parent");
      var child = document.getElementById("child");
      document.getElementById("result").innerHTML = parent.hasChildNodes();
   </script>
</body>
</html>
Copy after login

To summarize, there are several ways to check if a parent element contains a child element. You can use the Node.contains() or hasChildNodes() method.

The above is the detailed content of How to return true in JavaScript if parent element contains child elements?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
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

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

What should I do if I encounter garbled code printing for front-end thermal paper receipts? What should I do if I encounter garbled code printing for front-end thermal paper receipts? Apr 04, 2025 pm 02:42 PM

Frequently Asked Questions and Solutions for Front-end Thermal Paper Ticket Printing In Front-end Development, Ticket Printing is a common requirement. However, many developers are implementing...

Who gets paid more Python or JavaScript? Who gets paid more Python or JavaScript? Apr 04, 2025 am 12:09 AM

There is no absolute salary for Python and JavaScript developers, depending on skills and industry needs. 1. Python may be paid more in data science and machine learning. 2. JavaScript has great demand in front-end and full-stack development, and its salary is also considerable. 3. Influencing factors include experience, geographical location, company size and specific skills.

Demystifying JavaScript: What It Does and Why It Matters Demystifying JavaScript: What It Does and Why It Matters Apr 09, 2025 am 12:07 AM

JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.

How to merge array elements with the same ID into one object using JavaScript? How to merge array elements with the same ID into one object using JavaScript? Apr 04, 2025 pm 05:09 PM

How to merge array elements with the same ID into one object in JavaScript? When processing data, we often encounter the need to have the same ID...

How to achieve parallax scrolling and element animation effects, like Shiseido's official website?
or:
How can we achieve the animation effect accompanied by page scrolling like Shiseido's official website? How to achieve parallax scrolling and element animation effects, like Shiseido's official website? or: How can we achieve the animation effect accompanied by page scrolling like Shiseido's official website? Apr 04, 2025 pm 05:36 PM

Discussion on the realization of parallax scrolling and element animation effects in this article will explore how to achieve similar to Shiseido official website (https://www.shiseido.co.jp/sb/wonderland/)...

The difference in console.log output result: Why are the two calls different? The difference in console.log output result: Why are the two calls different? Apr 04, 2025 pm 05:12 PM

In-depth discussion of the root causes of the difference in console.log output. This article will analyze the differences in the output results of console.log function in a piece of code and explain the reasons behind it. �...

Is JavaScript hard to learn? Is JavaScript hard to learn? Apr 03, 2025 am 12:20 AM

Learning JavaScript is not difficult, but it is challenging. 1) Understand basic concepts such as variables, data types, functions, etc. 2) Master asynchronous programming and implement it through event loops. 3) Use DOM operations and Promise to handle asynchronous requests. 4) Avoid common mistakes and use debugging techniques. 5) Optimize performance and follow best practices.

How to implement panel drag and drop adjustment function similar to VSCode in front-end development? How to implement panel drag and drop adjustment function similar to VSCode in front-end development? Apr 04, 2025 pm 02:06 PM

Explore the implementation of panel drag and drop adjustment function similar to VSCode in the front-end. In front-end development, how to implement VSCode similar to VSCode...

See all articles