Undefined variable in boostrap modal - Laravel

I have a $room variable inside a bootstrap modal and it is causing the problem here is the function in the reservationController

    {
        $room=Room::all();
        return view('/allReservationChild', compact('room'));
    }

the blade name is allReservationChild.blade.php and this is the part of the modal :

```<div class="modal fade" id="addres" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
    <div class="modal-dialog modal-dialog-centered" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="exampleModalLongTitle">Delete Room</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                    <span aria-hidden="true">&times;</span>
                </button>
            </div>
            <form style="margin: 50px; text-transform: capitalize " action="/addReservation" method="POST" class="needs-validation" novalidate >
                @csrf

                <div class="modal-body">
                    <div class="form-group">
                        <label for="exampleFormControlSelect1">Select the Room you want to reserve</label>
                        <select class="form-control" id="exampleFormControlSelect1" name="room_id" required>
                            <option value=""></option>
                            @foreach($room as $items)
                                <option value=""></option>
                            @endforeach

                        </select>
                    </div>


                    <div class="mb-3">
                        <label for="exampleFormControlTextarea1" class="form-label">Objectif :</label>
                        <select class="form-control" id="exampleFormControlTextarea1" name="objectif" required>
                            <option value=""></option>
                            <option value="Booking room for a replacement session ">Booking room for a replacement session </option>
                            <option value="Booking room for a random session">Booking room for a random session</option>
                            <option value="Booking room for an event">Booking room for an event</option>
                            <option value="Booking room for an exam">Booking room for an exam</option>
                            <option value="Booking room for discussion of the graduation thesis">Booking room for discussion of the graduation thesis</option>
                            <option value="other">other</option>
                        </select>
                    </div>


                    <div class="form-group">
                        <label class="control-label">Reservation date</label></br>
                        <input class="form-control" type="date" id="Date_beginning" name="date" required>
                    </div>

                    <div class="form-group">
                        <label for="time">Select time period</label>
                        <select class="form-control" id="time" name="time" required>
                            <option value=""></option>
                            <option value="8:30-10:30">8.30-10.30</option>
                            <option value="10:30-12:30">10.30-12.30</option>
                            <option value="13:30-15:30">13.30-15.30</option>
                        </select>
                    </div>

                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-outline-secondary" data-dismiss="modal">Close</button>
                    <button type="submit" class="btn btn-outline-danger" name="supp" >Add Reservation</button>
                </div>
            </form>

        </div>
    </div>
</div>

and for the **web** 

 ```Route::get('/addReservation',[\App\Http\Controllers\reservationController::class,'create']);

I don't know why ha can not know define the $room variable I think it is because of the modal or something. and the modal I'm sure it is right because I used the same modal in another blade and it works perfectly so the problem I think is in the controller or the web I am not sure

via Chebli Mohamed