# .has()

## has ( selector ) Returns: jQuery version added: 1.4

- selector
  Type: String
  A string containing a selector expression to match elements against.

## has ( contained ) Returns: jQuery version added: 1.4

- contained
  Type: Element
  A DOM element to match elements against.

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

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.

## Examples:

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

    <!doctype html>
    <html lang="en">
    <head>
      <meta charset="utf-8">
      <title>css demo</title>

      <style>

      .full {
        border: 1px solid red;
      }

      </style>

      <script src="//code.jquery.com/jquery-1.10.2.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: