Find the position of an element within a list

I'm looking to find the position (i.e. the order) of a clicked element within a list using jQuery.

I have:

<ul>
 <li>Element 1</li>
 <li>Element 2</li>
 <li>Element 3</li>
 ...
</ul>

On click of an <li>, I want to store it's position within a variable. For example, if I clicked on Element 3, then "3" would be stored in a variable.

How could this be achieved?

Thanks much for y开发者_如何学JAVAour help!

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Use index():

$("li").click(function() {
  var index = $(this).parent().children().index(this);
  alert("You clicked item " + index);
});

Indexes start at 0.

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A more efficient version of Cletus' answer, which doesn't require finding parents and children:

$("li").on("click", function() {
  var index = $(this).index();
  alert(index);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul>
 <li>Element 1</li>
 <li>Element 2</li>
 <li>Element 3</li>
 <li>Element 4</li>
</ul>

---

Can also be done with plain JavaScript:

let = _this = this,
      indx = Array.prototype.slice.call(_this.parentElement.childNodes).indexOf(_this);

Or, if you trying to style your ordered html list with other than CSS like <hr>, as @Jan mentioned, use querySelectorAll('li') instead of childNodes.

---

Previous answer works fine. 2 additions:
When your list contains listitems of <a> for example:

<ul id="test">
  <li><a href="#">Element 1</a></li>
  <hr /><hr />
  <li><a href="#">Element 2</a></li>
  <li><a href="#">Element 3</a></li>
</ul>

then you have to use var index = $(this).parent().parent().children().index(this);

Also like in above example the list contains other elements like <hr /> than you can use a filter in var index = $(this).parent().parent().children("li").index(this); to give you index 2 for "element 3" instead of index 4.