JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo" data-num="0"></div> <a href="#" id="changeData">change data value</a>

JavaScript

$('#changeData').click(function (e) { 
    e.preventDefault();
    var num = +$('#foo').attr("data-num");
    console.log(num);
    num = num + 1;
    console.log(num);
    $('#foo').attr('data-num', num);
});