Why can't if part not executed in laravel 5 controller method? - laravel-5

Question

public function index1()
{
// $g = Request::input('grade');
//$s = Request::input('subject');
$g=$_POST['grade'];
$s=$_POST['subject'];
if(strcmp($g,'Select A Grade')==0 || strcmp($s,'Select A Subject')==0){
if(strcmp($s,'Select A Subject')!=0){
// Session::flash('msg', 'Please select the Subject.');
return redirect()->back()->withInput();
}
else if(strcmp($g,'Select A Grade')!=0){
// Session::flash('msg', 'Please select the Grade.');
return redirect()->back()->withInput();
}
}
else{
$u = DB::table('upldtbls')->where('grade',$g)->where('subject',$s)->get();
return view('2Eng',compact('u'));
}
}
Above is the controller method. Main else part executed correctly. But main if part not executed I guess. In main if condition I want to stay on the same page if drop box values are equal to that. Can any one figure out this mess?

Answer 1

I guess this is what you what to do:
if(strcmp($s,'Select A Subject') !== 0 ){
// Session::flash('msg', 'Please select the Subject.');
return redirect()->back()->withInput();
}
else if(strcmp($g,'Select A Grade') !== 0 ){
// Session::flash('msg', 'Please select the Grade.');
return redirect()->back()->withInput();
}
Ps.
Don't use $_POST, use this:
https://laravel.com/docs/5.2/requests
And for validation its more convenient to use:
https://laravel.com/docs/5.1/validation