从mdl单选按钮获取值

<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="option1">
  <input type="radio" id="option1" class="mdl-radio__button" name="options" value="option1" checked>
  <span class="mdl-radio__label">Option 1</span>
</label>
<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="option2">
  <input type="radio" id="option2" class="mdl-radio__button" name="options" value="option2">
  <span class="mdl-radio__label">Option 2</span>
</label>
<label class="mdl-radio mdl-js-radio mdl-js-ripple-effect" for="option3">
  <input type="radio" id="option3" class="mdl-radio__button" name="options" value="option3">
  <span class="mdl-radio__label">Option 3</span>
</label>
<button onclick="getSelectedOption()">Get Selected Option</button>

function getSelectedOption() {
  var options = document.getElementsByName('options');
  var selectedOption;

  for (var i = 0; i < options.length; i++) {
    if (options[i].checked) {
      selectedOption = options[i].value;
      break;
    }
  }

  if (selectedOption) {
    console.log('Selected Option: ' + selectedOption);
  } else {
    console.log('No option selected');
  }
}