如何以数字形式获取单选按钮值

<form>
  <input type="radio" id="option1" name="radioGroup" value="option1">
  <label for="option1">选项1</label><br>
  <input type="radio" id="option2" name="radioGroup" value="option2">
  <label for="option2">选项2</label><br>
  <input type="radio" id="option3" name="radioGroup" value="option3">
  <label for="option3">选项3</label><br>
</form>
<button onclick="getSelectedValue()">获取选中值</button>

function getSelectedValue() {
  var radios = document.getElementsByName('radioGroup');
  var selectedValue;

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

  console.log(selectedValue);
}