How to determine if an element has child elements in jquery-Front-end Q&A-php.cn

How to determine if an element has child elements in jquery

青灯夜游

Release： 2022-07-05 19:11:02

Original

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Judgment steps: 1. Use children() to obtain all direct subset elements of the specified element. The syntax "specified element object.children();" will return a jquery object containing subset elements; 2. Use the length attribute to count the number of subset elements in the jquery object, the syntax is "jquery object.length"; 3. Use the ">=" operator to determine whether the number of subset elements is greater than or equal to 1, the syntax is "number of elements> ;=1", if it is greater than or equal to 1, there are child elements, otherwise there are no child elements.

How to determine if an element has child elements in jquery

The operating environment of this tutorial: windows7 system, jquery3.6.0 version, Dell G3 computer.

jquery method to determine whether an element has child elements

In jquery, you can use the children() method and length attribute to determine whether an element has child elements. Whether the element has child elements.

Implementation steps:

Step 1: Use children() to get all direct subset elements of the specified element

指定元素对象.children();

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Will return a jquery object containing subset elements

Step 2: Use the length attribute to count the number of subset elements in the jquery object

jquery对象.length

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Step 3: Use the ">=" operator to determine whether the number of subset elements is greater than or equal to 1

子集元素的个数>=1

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If it is greater than or equal to 1, then there are children in the specified element Element
If less than 1, there are sub-elements in the specified element

Implementation code:

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<script src="js/jquery-3.6.0.min.js"></script>
		<script type="text/javascript">
			$(document).ready(function() {
				$("button").click(function() {
					$len=$("div").children().length;
					if ($len>=1) {
						console.log("指定元素中有子元素");
					} else {
						console.log("指定元素中没有子元素");
					}
				});
			});
		</script>
	</head>

	<body>
		<div style="border: 1px solid red;">
			<p>子元素1</p>
			<span>子元素2</span>
			<span>子元素2</span>
			<p>子元素3</p>
			<p>子元素4</p>
		</div><br>
		<button>指定div元素是否有子元素</button>
	</body>
</html>

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How to determine if an element has child elements in jquery

[Recommended learning: jQuery video tutorial, web front-end video]

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