aboot单选按钮验证

<form>
  <input type="radio" name="gender" value="male"> Male<br>
  <input type="radio" name="gender" value="female"> Female<br>
  <input type="radio" name="gender" value="other"> Other<br>
  <input type="submit" value="Submit">
</form>

<script>
  const form = document.querySelector('form');
  const radios = form.elements['gender'];

  form.addEventListener('submit', function(event) {
    let selected = false;
    for (let i = 0; i < radios.length; i++) {
      if (radios[i].checked) {
        selected = true;
        break;
      }
    }

    if (!selected) {
      event.preventDefault(); // 阻止表单提交
      alert('请选择一个选项');
    }
  });
</script>