/**
  * Display a listing of the resource.
  *
  * @return \Illuminate\Http\Response
  */
 public function index()
 {
     $promos = Promo::all();
     foreach ($promos as $promo) {
         $promo->nbStudent = count(Student::where('promo', $promo->id)->get());
     }
     return view('admin.promo.list', compact('promos'));
 }
 /**
  * Remove the specified resource from storage.
  *
  * @param  int  $id
  * @return \Illuminate\Http\Response
  */
 public function destroy($id)
 {
     $student = Student::findOrFail($id);
     $student->delete();
     return redirect('admin/Student');
 }