# .has()

Categories: Traversing > Filtering

## .has( selector ) Returns: 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:

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

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.

### Example:

#### Check if an element is inside another.

    <!DOCTYPE html>
    <html>
    <head>
      <style>
      .full { border: 1px solid red; }
    </style>
      <script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
    </head>
    <body>

    <ul><li>Does the UL contain an LI?</li></ul>

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

    </body>
    </html>

#### Demo: