Closest () a function that is useful in comments

Instance

This example demonstrates how to complete an event delegate through closest (). When clicked by the closest list element or its child descendant elements, the yellow background is toggled:

$ (document). Bind ("click", Function (e) {    $ (e.target) .closest("li") . Toggleclass ("Hilight");  });

Definition and usage

The closest () method obtains the first ancestor element of a matching selector, starting at the current element along the DOM tree.

Grammar

. Closest (selector)

Parameters	Description
Selector	A string value that contains the selector expression for the matching element.

Detailed description

Given a JQuery object that represents a collection of DOM elements, the. Closest () method allows us to retrieve these elements in the DOM tree and their ancestor elements, and constructs a new JQuery object with matching elements: similar to the parents () and. Closest () methods, they all follow the The DOM tree is traversed upward. The difference between the two is very important, albeit subtle:

. Closest ()	. Parents ()
Start with the current element	Start with the parent element
Walk up the DOM tree until you find a match for the selector you have applied.	Iterates up the DOM tree until the root element of the document, adding each ancestor element to a temporary collection, and if the selector is applied, the collection is filtered based on that selector.
Returns a JQuery object that contains 0 or one element	Returns a JQuery object that contains 0, one, or more elements

Take a look at the following HTML snippet:

<ul id= "One" class= "Level-1" >  <li class= "item-i" >I</li>  <li id= "II" class= "Item-ii" >ii  <ul class= "Level-2" >    <li class= "item-a" >A</li>    <li class= "Item-b" >b      <ul class= "level-3" >        <li class= "item-1" >1</li>        <li class= "Item-2" >2</li >        <li class= "item-3" >3</li>      </ul>    </li>    <li class= "Item-c" > c</li>  </ul>  </li>  <li class= "ITEM-III" >III</li></ul>

Example 1

Let's say we perform a search for the <ul> element starting with Project A:

$ (' li.item-a '). Closest (' ul '). CSS (' background-color ', ' red ');

This changes the color of the Level-2 <ul> because it is the first to be encountered when walking up the DOM tree.

Example 2

Let's say we're searching for <li> elements:

$ (' li.item-a '). Closest (' Li '). css (' background-color ', ' red ');

Closest () a function that is useful in comments