JSFiddle - React, Tailwind, and code Playground

by DupontTD

HTML

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
<div>item 1</div>
<div>item 2</div>
<div>item 3</div>
<div>item 4</div>
<div>item 5</div>
<div>item 6</div>
</body>
</html>

CSS

.blue{
  color : blue;
}

.blue:before{
  content : "**"
}

JavaScript

let elements = document.querySelectorAll("div:nth-child(2n)"),
    color = el =>  el.classList.add("blue");

// Spread operateur
[...elements].forEach(color);

elements.forEach(color);