JSFiddle - React, Tailwind, and code Playground

HTML

<button>test</button>

<p id="huy"></p>
<p id="op"></p>

JavaScript

var count = 0;
var button = document.querySelector('button');
var p = document.querySelector('#huy');
var op = document.querySelector('#op');
p.innerHTML = count;
    button.addEventListener('click', function() {
    count++;
    //button.innerHTML = count;
    p.innerHTML = count;  
    op.innerHTML = (count-10) * 2;
});