JSFiddle - React, Tailwind, and code Playground

HTML

<input id="i" value="" class="A">

JavaScript

document.addEventListener('DOMContentLoaded', function(event) {
	//1) OK - should display A in console
	console.log('1)should be A:', i.className)

  //2) OK - input field should have B class
	i.className = 'B'

	//3) OK - should display B in console
	console.log('3)should be B:', i.attributes.class.nodeValue)
  
  //4) OK - input field should have C class
	i.attributes.value.nodeValue = 'C'
})