JSFiddle - React, Tailwind, and code Playground

HTML

<div id="elem" data-k1="hello"></div>

JavaScript

var elem = $( "#elem" );

console.log( "k1 pre: " + elem[0].dataset.k1 );

elem.attr( "data-k1", "changed" );
console.log( "k1 post: " + elem[0].dataset.k1 );

elem.attr( "data-k2", "set" );
console.log( "k2: " + elem[0].dataset.k2 );