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<!DOCTYPE html>
<html lang='en'><head><meta http-equiv='content-type' content='text/html; charset=UTF-8' /></head><body>
<div class="entry-content">
<div class="entry-title roundTop">
<h1 class="jq-clearfix">.index()</h1>
<div class="entry-meta jq-clearfix">
Categories:
<span class="category"><a href="http://api.jquery.com/category/miscellaneous/" title="View all posts in Miscellaneous">Miscellaneous</a> > <a href="http://api.jquery.com/category/miscellaneous/dom-element-methods/" title="View all posts in DOM Element Methods">DOM Element Methods</a></span>
</div>
</div>
<div id="index1" class="entry method">
<h2 class="jq-clearfix roundTop section-title">
<span class="name">.index( )</span> <span class="returns">Returns: <a class="return" href="http://api.jquery.com/Types/#Number">Number</a></span>
</h2>
<div class="jq-box roundBottom entry-details">
<p class="desc"><strong>Description: </strong>Search for a given element from among the matched elements.</p>
<ul class="signatures">
<li class="signature" id="index"><h4 class="name">
<span class="versionAdded">version added: <a href="/category/version/1.4/">1.4</a></span>.index()</h4></li>
<li class="signature" id="index-selector">
<h4 class="name">
<span class="versionAdded">version added: <a href="/category/version/1.4/">1.4</a></span>.index( selector )</h4>
<p class="arguement"><strong>selector</strong>A selector representing a jQuery collection in which to look for an element.</p>
</li>
<li class="signature" id="index-element">
<h4 class="name">
<span class="versionAdded">version added: <a href="/category/version/1.0/">1.0</a></span>.index( element )</h4>
<p class="arguement"><strong>element</strong>The DOM element or first element within the jQuery object to look for.</p>
</li>
</ul>
<div class="longdesc">
<h4>Return Values</h4>
<p>If no argument is passed to the <code>.index()</code> method, the return value is an integer indicating the position of the first element within the jQuery object relative to its sibling elements.</p>
<p>If <code>.index()</code> is called on a collection of elements and a DOM element or jQuery object is passed in, <code>.index()</code> returns an integer indicating the position of the passed element relative to the original collection.</p>
<p>If a selector string is passed as an argument, <code>.index()</code> returns an integer indicating the position of the original element relative to the elements matched by the selector. If the element is not found, <code>.index()</code> will return -1.</p>
<h4>Detail</h4>
<p>The complementary operation to <code>.get()</code>, which accepts an index and returns a DOM node, <code>.index()</code> can take a DOM node and returns an index. Suppose we have a simple unordered list on the page:</p>
<pre>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
</pre>
<p>If we retrieve one of the three list items (for example, through a DOM function or as the context to an event handler), <code>.index()</code> can search for this list item within the set of matched elements:</p>
<pre>
var listItem = document.getElementById('bar');
alert('Index: ' + $('li').index(listItem));
We get back the zero-based position of the list item:
</pre>
<p><span class="output">Index: 1</span></p>
<p>Similarly, if we retrieve a jQuery object consisting of one of the three list items, <code>.index()</code> will search for that list item:</p>
<pre>
var listItem = $('#bar');
alert('Index: ' + $('li').index(listItem));
</pre>
<p>We get back the zero-based position of the list item:</p>
<p><span class="output">Index: 1</span></p>
<p>Note that if the jQuery collection used as the <code>.index()</code> method's argument contains more than one element, the first element within the matched set of elements will be used.</p>
<pre>
var listItems = $('li:gt(0)');
alert('Index: ' + $('li').index(listItems));
</pre>
<p>We get back the zero-based position of the first list item within the matched set:</p>
<p><span class="output">Index: 1</span></p>
<p>If we use a string as the <code>.index()</code> method's argument, it is interpreted as a jQuery selector string. The first element among the object's matched elements which also matches this selector is located.</p>
<pre>
var listItem = $('#bar');
alert('Index: ' + listItem.index('li'));
</pre>
<p>We get back the zero-based position of the list item:</p>
<p><span class="output">Index: 1</span></p>
<p>If we omit the argument, <code>.index()</code> will return the position of the first element within the set of matched elements in relation to its siblings:</p>
<pre>alert('Index: ' + $('#bar').index();</pre>
<p>Again, we get back the zero-based position of the list item:</p>
<p><span class="output">Index: 1</span></p>
</div>
<h3>Examples:</h3>
<div class="entry-examples" id="entry-examples">
<div id="example-0">
<h4>Example: <span class="desc">On click, returns the index (based zero) of that div in the page.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>
div { background:yellow; margin:5px; }
span { color:red; }
</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<span>Click a div!</span>
<div>First div</div>
<div>Second div</div>
<div>Third div</div>
<script>
$("div").click(function () {
// this is the dom element clicked
var index = $("div").index(this);
$("span").text("That was div index #" + index);
});
</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-1">
<h4>Example: <span class="desc">Returns the index for the element with ID bar.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>div { font-weight: bold; color: #090; }</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
<div></div>
<script>var listItem = $('#bar');
$('div').html( 'Index: ' + $('li').index(listItem) );</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-2">
<h4>Example: <span class="desc">Returns the index for the first item in the jQuery collection.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>div { font-weight: bold; color: #090; }</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
<div></div>
<script>var listItems = $('li:gt(0)');
$('div').html( 'Index: ' + $('li').index(listItems) );
</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-3">
<h4>Example: <span class="desc">Returns the index for the element with ID bar in relation to all <li> elements.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>div { font-weight: bold; color: #090; }</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
<div></div>
<script>$('div').html('Index: ' + $('#bar').index('li') );</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-4">
<h4>Example: <span class="desc">Returns the index for the element with ID bar in relation to its siblings.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>div { font-weight: bold; color: #090; }</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
<div></div>
<script>var barIndex = $('#bar').index();
$('div').html( 'Index: ' + barIndex );</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-5">
<h4>Example: <span class="desc">Returns -1, as there is no element with ID foobar.</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>div { font-weight: bold; color: #090; }</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<ul>
<li id="foo">foo</li>
<li id="bar">bar</li>
<li id="baz">baz</li>
</ul>
<div></div>
<script>var foobar = $("li").index( $('#foobar') );
$('div').html('Index: ' + foobar);</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
</div>
</div>
</div>
</div>
</body></html>
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