我有一個帶有多選下拉菜單的表單<form role="form" method="post" action="{{route('dev-admin.developer-contractor-associations.add.post')}}" autocomplete="off">        <div class="col-12">            @csrf            <div class="form-group {{ $errors->has('defect-type-id') ? ' has-danger' : '' }}">                <select class="selectpicker {{ $errors->has('defect-type-id') ? 'is-invalid' : '' }}" name="defect-type-id" id="defect-type-id" multiple data-style="selectpicker-style" data-width="100%" title="Defect Types">                    @foreach(App\DefectType::select('id','title')->get() as $defect_type)                        <option value="{{$defect_type->id}}">{{$defect_type->title}}</option>                    @endforeach                </select>                @if ($errors->has('defect-type-id'))                <span class="invalid-feedback" role="alert">                    <strong>{{ $errors->first('defect-type-id') }}</strong>                </span>                @endif            </div>        </div>        <div class="col-12">        <div class="text-center">            <button onclick="return confirm('Are you sure to associate this contractor?')" type="submit" class="btn btn-primary my-4">Associate</button>        </div>    </div></form>當我想獲取控制器中的值時，我只收到 1 個選定值而不是選定選項列表：public function postAddDeveloperContractorAssociation(Request $request ) {    $defect_type_id = $request->input('defect-type-id');    dd($defect_type_id);    return redirect()->route('dev-admin.developer-contractor-associations.index')->withStatus(__('Contractor has been added.'));}當我dd這一切時，我得到的是類似的東西"2"而不是類似的[1, 2, 3]東西