JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="master">
<li id="1" class="elem">1</li>
<li id="2" class="elem">2</li>
<li id="3" class="elem">3</li>
<li id="4" class="elem">4</li>
</ul>

JavaScript

// storing .elem in a variable
var obj = $(".elem");

// logging both values to the console
console.log("obj length before: " + obj.length)
console.log(".elem length before " + $(".elem").length)

// remove DOM Element
$("#3").remove();

// Logging obj to the console
// obj has still 4 items and the removed div  
console.log(obj);
console.log("obj length after: " + obj.length)
    
// Logging $(".elem") to the console
// 3 .elems
console.log($(".elem"));
console.log(".elem length after " + $(".elem").length)

//Updating values on .elem are reflected on obj    
$(".elem").css("width",300);
console.log("new width: " + obj.width());

// Adding Stuff to the DOM won't be in obj :-/
$("<li id='5' class='elem'>5</li>").appendTo($("#master"));
console.log(obj);
console.log($(".elem"));