JSFiddle - React, Tailwind, and code Playground

HTML

<div id=div1>AAAA</div1><div id=div2>AAAA</div1>

CSS

div {
  display:none;   
}

JavaScript

var counter = 0;
    $.when($("#div1, #div2").fadeIn(3000)).done(function(){
      counter++;
    console.log(counter);
    });