.has() in JQuery


Description: Reduce the set of matched elements to those that have a descendant that matches the selector or DOM element.

  • version added: 1.4.has( selector )

    selectorA string containing a selector expression to match elements against.

  • version added: 1.4.has( contained )

    containedA DOM element to match elements against.

Given a jQuery object that represents a set of DOM elements, the .has() method constructs a new jQuery object from a subset of the matching elements. The supplied selector is tested against the descendants of the matching elements; the element will be included in the result if any of its descendant elements matches the selector.

Consider a page with a nested list as follows:

  <li>list item 1</li>
  <li>list item 2
      <li>list item 2-a</li>
      <li>list item 2-b</li>
  <li>list item 3</li>
  <li>list item 4</li>

We can apply this method to the set of list items as follows:

$('li').has('ul').css('background-color', 'red');

The result of this call is a red background for item 2, as it is the only <li> that has a <ul> among its descendants.


Check if an element is inside another.

<!DOCTYPE html>
  .full { border: 1px solid red; }
  <script src="/scripts/jquery-1.4.js"></script>
<ul><li>Does the UL contain an LI?</li></ul>

  $("ul").append("<li>" + ($("ul").has("li").length ? "Yes" : "No") + "</li>");

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