:even Selector

Categories: Selectors > Basic Filter | Selectors > jQuery Extensions Chinese Translation: :even Selector

even selector

Description: Selects even elements, zero-indexed. See also odd.

  • version added: 1.0jQuery( ":even" )

In particular, note that the 0-based indexing means that, counter-intuitively, :even selects the first element, third element, and so on within the matched set.

Additional Notes:

  • Because :even is a jQuery extension and not part of the CSS specification, queries using :even cannot take advantage of the performance boost provided by the native DOM querySelectorAll() method. To achieve the best performance when using :even to select elements, first select the elements using a pure CSS selector, then use .filter(":even").
  • Selected elements are in the order of their appearance in the document.

Example:

Finds even table rows, matching the first, third and so on (index 0, 2, 4 etc.).

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<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>even demo</title>
  <style>
  table {
    background: #eee;
  }
  </style>
  <script src="https://code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
 
<table border="1">
  <tr><td>Row with Index #0</td></tr>
  <tr><td>Row with Index #1</td></tr>
  <tr><td>Row with Index #2</td></tr>
  <tr><td>Row with Index #3</td></tr>
</table>
 
<script>
$( "tr:even" ).css( "background-color", "#bbf" );
</script>
 
</body>
</html>

Demo: