JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

* { font-family: monospace; }

JavaScript

jQuery(function($){

    var div = $("div");
    
    // $.fn.data() case
    div.data("name", "name data");
    div.data("name.subdata", "subdata"); 
    div.data("name.removeme", "removeme"); 
    
    div.removeData("name.removeme");
    
    div.append("$.fn.data():"); 
    
    div.append("<br>I want this subdata   -> " + div.data("name.subdata"));
    div.append("<br>I want this undefined -> " + div.data("name.removeme"));
    div.append("<br>I want this undefined -> " + div.data("name.whatevs")); 

    // $.data() case
    $.data(div, "name", "name data"); 
    $.data(div, "name.subdata", "subdata");  
    $.data(div, "name.removeme", "removeme");  
    
    $.removeData(div, "name.removeme");
    
    div.append("<br><br>$.data():");
    
    div.append("<br>I want this subdata   -> " + $.data(div, "name.subdata"));
    div.append("<br>I want this undefined -> " + $.data(div, "name.removeme"));
    div.append("<br>I want this undefined -> " + $.data(div, "name.whatevs"));

});