Make sure the name attribute is assigned to the array
<select multiple="multiple" name="news[]" id="news">
,
$news = $request->input('news');
$news = implode(',', $news);
, Users,staff,cinemahall. , , , news. , except() news , .
$news = $request->input('news');
$news = implode(',', $news);
$input = $request->except('news');
$input['news'] = $news;
General_news::create($input);
return redirect()->back();