JSFiddle - React, Tailwind, and code Playground

HTML

<div id="list">
  <div class="good">first</div>
  <div class="good">second</div>
  <div>trash</div>
  <div class="good">third</div>
</div>

JavaScript

function getIndex(obj) {
    var $objectArray = $("#list").children(".good");
    return $.inArray($(obj), $objectArray);
}

$(document).ready(function () {
    $("#list").children(".good").click(function () {
         var index =  $("#list").children(".good").index(this);
        alert(index);
    });
});