Tryit Editor v1.8

Source Code:

<!DOCTYPE html>
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js">
</script>
<script>
$(document).ready(function(){
  $("li").click(function(){
    alert($(this).index());
  });
});
</script>
</head>
<body>

<p>Click the list items to get the index position, relative to its sibling elements</p>

<ul>
<li>Coffee</li>
<li>Milk</li>
<li>Soda</li>
</ul>

</body>
</html>

Result:

W3Schools.com - Try it yourself

Edit the code above and click "Submit Code" to see the result.