此代码在 Javascript 中会是什么样子?

What will this code look like in Javascript?

我有问题,我在Jquery写了代码,工人要求不要用。此函数应检查输入是否完整

$('document').ready(function() {
    $('#btn').on('click', function() {
      $('.registration__labels .rfield').each(function() {
        if ($(this).val() == '') {
            console.log(2);
            $('input[required]').addClass('error');
        } else {
            console.log(1);
            $('input[required]').removeClass('error');
        }
      });
    });
});

这是 Jquery 代码,有效

document.addEventListener('DOMContentLoaded',function validation (){
  if(btn.addEventListener("click", function() {
    ('.registration__labels .rfield').forEach(() => {
        if (document.getElementsByClassName('input[type=text]').value == '') {
          console.log(2);
          (".input[required]").classList.add('error');
        }
        else {
          console.log(1);
          (".input[required]").classList.remove('error');
        }
      }
  )}))[validation]});

这是我试图将其翻译成 javascript 但它不起作用。请帮助我

一种方法...

window.addEventListener('DOMContentLoaded', () => 
  {
  const allRegLabs = document.querySelectorAll('.registration__labels .rfield')  

  document.querySelector('#btn').onclick = () =>
    {
    allRegLabs.forEach( el =>
      {
      let err =  el.classList.toggle('error', (el.value === ''))
      console.log( (err ? '2':'1' ))
      })
    }
  })