Laravel: Undefined variable after a post action - laravel

Question

I'm making profile edit page and I had a problem after post action.
Routes file is
Route::get('profile', 'ProfileController#profile')->name('profile');
Route::post('profile', 'ProfileController#update');
Profile page Controller
public function profile()
{
$cities = City::all();
$current_city = Auth::user()->city;
$current_city_name = City::cityName($current_city);
return view('profile.edit', compact('cities', 'current_city', 'current_city_name'));
}
protected function validator(array $data)
{
return Validator::make($data, [
'email' => 'required|string|email|max:255',
]);
}
public function update(Request $request)
{
$this->validator($request->all())->validate();
$user = Auth::user();
$user->email = $request->input('email');
$user->city = $request->input('city');
$user->save();
$request->session()->flash('message', 'Information successfully changed');
return view('profile.edit');
}
And finally blade template code
<select name="city" id="city" class="form-control">
<option value="{{ $current_city }}">{{ $current_city_name }}</option>
#foreach ($cities as $city)
<option value="{{ $city->id }}">{{ $city->name }}</option>
#endforeach
</select>
First entrance on profile page is ok. But after form submitting I have an error
Undefined variable: current_city (View: C:\OSPanel\domains\ang\laravel\resources\views\profile\edit.blade.php)

Answer 1

You're not passing any variables to the view in your update() method, but returning the same view (that expects those variables) here:
public function update(Request $request)
{
// ...
return view('profile.edit');
}
You could simply redirect back:
public function update(Request $request)
{
// ...
return back();
}