const div = document.createElement('div')
const input = document.createElement('input')

input.setAttribute('type', 'text')

input.addEventListener('change', (e) => {
  if (text === '') {
    return updateDiv({ text, className: 'hidden'})
  }
  
  updateDiv(text, className: 'my-class')
});

const updateDiv = ({ text, className }) => {
  div.innerText = text
  
  if (className !== div.getAttribute('class')) {
    div.setAttribute('class', className)
  }
}

document.body.appendElement(div)
document.body.appendElement(input)

updateDiv({ text: 'I\'m some text', className: 'my-class' })