javascript - 使用开关盒进行 radio 更改

Question

我正在制作下面的演示。为什么我得到 undefined 当我选择No时选项，但选择Yes正在返回true ？

var unew;
$('input:radio[name=radios]').on('change', function () {
    var val = $('input:radio[name=radios]:checked').val();
     console.log(val);
    switch (val) {
        case 'false':
               console.log(unew);
               unew = false;
        break;            
        case 'true':
               unew = true;
               console.log(unew);
        break;

    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
        <div class="col-md-4 mb-4">
          <label for="booking-age">Are you Agree</label>
                    <div  class="p-0">
    <div class="btn-group btn-group-toggle my-1" data-toggle="buttons">
                    <label for="radios-0" class="btn btn-secondary rounded-0">
                      <input type="radio" name="radios" id="radios-0" value="true" >
                      Yes
                    </label>
                    <label for="radios-1" class="btn btn-secondary rounded-0">
                      <input type="radio" name="radios" id="radios-1" value="false" >
                      No 
                    </label>
                  </div>
                </div>
        </div>

Answer 1

在unew = false之后写入console.log