too long

HR_Helper.php

class HR_Helper{
    public static $Grade = array(1,2,3,4);
    public $work_shift = array("Work Shift","Regular Work Hours","Part Time");
    public $Salutation = array('Mr.','Miss','Mrs.','Ms.','Dr.'); 
    public $leave_types = array('Sick Leave','Maternity Leaves','Casual Leaves','Annual Leaves');    
    public $leave_status = array(0,1,2);        
}

Now i call these helper array in controller like that...

hrController.php

HR_Helper::Grade;

but it throw the following error

Class 'App\Http\Controllers\HR_H' not found

I also add these Helper in controller like that.. (use HR_R;)

HR_R helper is also added in the app.php -> aliases like 'HR_H' => App\Helpers\HR_Helper::class.

But it still not working...