JSFiddle - React, Tailwind, and code Playground

HTML

<h2>titulo</h2>

<p>texto</p>

CSS

h2
{
    font-weight:bolder;
    display: block;
    background-color: #CCCCCC;
}

JavaScript

alert(parseInt('08'));
alert(parseInt('08', 10));
alert(parseInt('010'));
alert(parseInt('09'));
alert(parseInt('09', 10));
alert(parseInt('011'));