JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test" data-testKey="test" data-test-key="second test" />

<div id="result" />

JavaScript

$(document).ready(function(){
    
    var $test = $('#test'),
        testData = $test.data(),
        testKey = $test.data('testKey'),
        testkey = $test.data('testkey');
    
    $('#result')
        .append('Test data: ' + JSON.stringify(testData) + '<br />')
        .append('testkey: ' + testkey+ '<br />')
        .append('testKey: ' + testKey);
});