I have two arrays of objects and I want to check if ids of elements of both are the same then select option in select box otherwise just display it. I tried like this:

<select multiple class="form-control" name="category_id[]">
                                @if(!$product->categories->isEmpty())
                                    @foreach($mysliwski as $mysl)
                                        @foreach($product->categories as $cat)
                                            @if($mysl->id == $cat->id)
                                                <option selected value="{{$mysl->id}}">{{$mysl->name}}</option>
                                            @else
                                                <option value="{{$mysl->id}}">{{$mysl->name}}</option>
                                            @endif
                                        @endforeach
                                    @endforeach
                                @else
                                    @foreach($mysliwski as $mysl)
                                        <option value="{{$mysl->id}}">{{$mysl->name}}</option>
                                    @endforeach
                                @endif
                                </select>

But it works only when one category is the same. When there are more my select option are duplicated. Here are my two arrays http://laravel.io/bin/ro5rM Where I have bug?