index(subject) → Number

Returns -1 if the object wasn't found.

Element subject : Object to search for.

Example:

On click, returns the index (based zero) of that div in the page.

$("div").click(function () {
      // this is the dom element clicked
      var index = $("div").index(this);
      $("span").text("That was div index #" + index);
    });

<span>Click a div!</span>
  <div>First div</div>
  <div>Second div</div>

  <div>Third div</div>

div { background:yellow; margin:5px; }
  span { color:red; }
  

Example:

Returns the index for the element with ID foobar.

$("*").index( $('#foobar')[0] )

<div id="foobar"><b></b><span id="foo"></span></div>

Example:

Returns the index for the element with ID foo within another element.

$("*").index( $('#foo')[0] )

<div id="foobar"><b></b><span id="foo"></span></div>

Example:

Returns the index for the element clicked within a collection.

var mainNavLinks = $('ul#mainNav li a');
mainNavLinks.click(function(){alert(mainNavLinks.index(this)0;});

Example:

Returns -1, as there is no element with ID bar.

$("*").index( $('#bar')[0] )

<div id="foobar"><b></b><span id="foo"></span></div>