선택한 확인란 값을 기준으로 드롭 다운 목록 옵션 가져 오기

< table class="table">
  < thead>
    < /thead>
      < th>
        <?php
           $oaNamesQuery = "SELECT DISTINCT oaName FROM oaDetails";
            $oaNamesQueryExecute = mysqli_query($conn, $oaNamesQuery);
             while($oaNamesQueryRow = mysqli_fetch_array($oaNamesQueryExecute)){
                   $oaName = $oaNamesQueryRow['oaName'];
                   echo '<div class = "checkbox-group" required style="float:left; margin-right: 25px;">                          <input class="checkBoxes" type="checkbox" id="checkBoxArray"             name="checkBoxArray[]" value="'.$oaName.'"> '.$oaName.'</div>';
                        }
                    ?>
          < /th>
            < /table>

<div class="col-sm">
  <label for="numberOfShiftPerDay">Number</label>
  <input type="number" class="form-control" id="numberOfShiftPerDay" name="numberOfShiftPerDay" placeholder="No: " onchange="disablingRoutine()" min="1" max="4">
</div>

if ($("#numberOfShiftPerDay").val() == 1) {
  $.each($("input[name='checkBoxArray[]']:checked"), function() {
    cval = $(this).val();
    $('#oaInShift1').append('<option>' + cval + '</option>')
  });
} else if ($("#numberOfShiftPerDay").val() == 2) {
  $.each($("input[name='checkBoxArray[]']:checked"), function() {
    cval = $(this).val();
    $('#oaInShift2').append('<option>' + cval + '</option>')
  });
} else if ($("#numberOfShiftPerDay").val() == 3) {
  $.each($("input[name='checkBoxArray[]']:checked"), function() {
    cval = $(this).val();
    $('#oaInShift3').append('<option>' + cval + '</option>')
  });
} else {
  $.each($("input[name='checkBoxArray[]']:checked"), function() {
    cval = $(this).val();
    $('#oaInShift4').append('<option>' + cval + '</option>')
  });
}