Radio fields check and uncheck

index.html

<input type="radio" name="1" class="radio">
<input type="radio" name="1" class="radio">
<input type="radio" name="1" class="radio">
<input type="radio" name="1" class="radio">
<br>
<input type="radio" name="2" class="radio">
<input type="radio" name="2" class="radio">
<input type="radio" name="2" class="radio">
<input type="radio" name="2" class="radio">

index.js

document.querySelectorAll('[type=radio]').forEach(item => {
  item.addEventListener('click', e => {
    const inputElement = e.target;
    const inputElementName = inputElement.getAttribute('name');
    const previouslyChecked = inputElement.getAttribute('previously-checked');

    if (previouslyChecked) {
        inputElement.checked = false;
        inputElement.removeAttribute('previously-checked');
    } else {
        const previouslyCheckedElement = document.querySelector('[name="' + inputElementName + '"][previously-checked]');
        if (previouslyCheckedElement) {
            previouslyCheckedElement.removeAttribute('previously-checked');
        }
      
        inputElement.setAttribute('previously-checked', 1);
    }
  });
});