如何将事件委托添加到单选按钮上的“更改”事件（而不是单击）？

Answer 1

您可以使用

input

 事件，该事件对任何表单元素也有效

演示：

const myForm = document.forms['my-form'];
  
myForm.addEventListener('submit', e => 
  {
  e.preventDefault(); // disable submit - page reload
  const formValues = Object.fromEntries(new FormData(myForm).entries());
  console.log( formValues );
  setInterval(console.clear,8000);
  })

myForm.addEventListener('input', e => 
  {
  if (!e.target.matches('input[type="radio"]')) return;
  
  console.log(myForm['difficulty-ask'].value);
  setInterval(console.clear,2000);
  });

label    { display:block; }
fieldset { width: fit-content; }

<form name="my-form">
  <fieldset>
    <legend> difficulty </legend>
    <label>
      <input name="difficulty-ask" type="radio" value="all" checked >
      All
    </label>
    <label>
      <input name="difficulty-ask" type="radio" value="easy" >
      Easy
    </label>
    <label>
      <input name="difficulty-ask" type="radio" value="medium" >
      Medium
    </label>
    <label>
      <input name="difficulty-ask" type="radio" value="hard" >
      Hard
    </label>
  </fieldset>
  <button>submit</button>
</form>