JSFiddle - React, Tailwind, and code Playground

HTML

<div class="div1">
    <div class="div2"></div>
</div>

CSS

.div1{width:100px; height:100px;overflow: auto;}
.div2{width:200px; height:200px;}

JavaScript

var width = $('.div1')[0]['clientWidth'];
var height = $('.div1')[0]['clientHeight'];
alert(width+'+'+height);