How to fix this error? ErrorException Use of undefined constant staff - assumed 'staff' (this will throw an Error in a future version of PHP)

Question

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\staff;

class staffController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        //
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        return view ('staff.create');
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)
    {
        $this->validate($request, [
            'staff_name' => 'required',
            'staff_dept' => 'required',
            'staff_phoneNo' => 'required'

        ]);
            $staff = new Staff([
                'staff_name' => $request->get('staff_name'),
                'staff_dept' => $request->get('staff_dept'),
                'staff_phoneNo' => $request->get('staff_phoneNo')
            ]);
            $staff->save();
            return redirect()->route(staff.create)->with('success','Data Added');
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        //
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        //
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        //
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        //
    }
}

Answer 1

return redirect()->route('staff.create')->with('success','Data Added');

Minor change in your code.