jQuery get index of nested element in relation to other nested elements with same class-CodePudding

First of all, sorry if the title isn't accurate, I can't think of a better title.

I have a similar structure like this:

<ol>
    <li>
        <ol>
            <li>1.</li>
            <li>2.</li>
            <li>3.</li>
            <li>4.</li>
        </ol>
    </li>
    <li>
        <ol>
            <li>1.</li>
        </ol>
    </li><li>
        <ol>
            <li >1.</li>
            <li>2.</li>
        </ol>
    </li><li>
        <ol>
            <li>1.</li>
        </ol>
    </li>
</ol>

Now I want to grab the active class with a selector and want to get the index of this li in relation to all li's. So in this example I should get "5" if it is zero-based.

I tried different things with index(), closest(), parent() and so on with no success. I only get 0 for the active li because it's the first li in "his" ordered list. I think somehow this should be possible and I hope, some of you can give me a hint.

CodePudding user response：

You can use an overload of jQuery's index().

If .index() is called on a collection of elements and a DOM element or jQuery object is passed in, .index() returns an integer indicating the position of the passed element relative to the original collection.

So create a collection of all the lis that you're interested in and then pass in the one that you want to find within that collection.

var idx = $("ol>li>ol>li").index($(".active"));

Using just $("li").index($(".active")) would not be enough as you have a number of li around the inner ols, so across "all li" the index would actually be 8.

console.log($("ol>li>ol>li").index($(".active")))

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ol>
  <li>
    <ol>
      <li>1.</li>
      <li>2.</li>
      <li>3.</li>
      <li>4.</li>
    </ol>
  </li>
  <li>
    <ol>
      <li>1.</li>
    </ol>
  </li>
  <li>
    <ol>
      <li >1.</li>
      <li>2.</li>
    </ol>
  </li>
  <li>
    <ol>
      <li>1.</li>
    </ol>
  </li>
</ol>