JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div id="content"></div>
</div>

CSS

#wrapper{
    overflow-y: scroll;
    height: 200px;
    width: 150px;
    background-color: yellow;
    border: 1px solid black;
}
#content{
    height: 500px;
    width: 40px;
    background-color: red;
    border: 1px solid green;
}

JavaScript

// This returns the height
console.log( $('#wrapper').height() );

// These return the scroll height
console.log( $('#wrapper')[0].scrollHeight );
console.log( document.getElementById("wrapper").scrollHeight );

// This will return undefined:
console.log( $('#wrapper').scrollHeight );