使用key参数对数组和数组数组进行排序

Question

我有一些学生，这些学生在变量$ arraytosort中获取，看起来像

       array(5027) { [0]=> array(5) { ["_id"]=> object(MongoId)#22 (1) { ["$id"]=> string(24) "58131c7799fbad4c1d000202" } ["fullname"]=> string(19) "David Robert Lara" ["firstmiddle"]=> string(12) "David Robert" ["firstlast"]=> string(14) "David Lara" ["student"]=> array(50) { ["_id"]=> object(MongoId)#23 (1) { ["$id"]=> string(24) "58131c7799fbad4c1d000202" } ["student_id"]=> float(2) ["registration_temp_perm_no"]=> string(1) "1" ["roll_no"]=> float(1) ["admission_date"]=> string(10) "01/07/2016" ["first_name"]=> string(7) "David" ["middle_name"]=> string(4) "Robert" ["last_name"]=> string(6) "Lara" ["dob"]=> string(10) "12/03/1981" ["gender"]=> string(6) "Female" ["blood_group"]=> string(2) "A+" ["birth_place"]=> string(11) "Sadar Bazar" ["nationality"]=> string(6) "Indian" ["language"]=> string(7) "English" ["religion"]=> string(8) "Agnostic" ["address_line1"]=> string(20) "4148 Hazelcrest Hill" ["address_line2"]=> string(20) "22883 Memorial Place" ["city"]=> string(11) "Sadar Bazar" ["state"]=> string(13) "Uttar Pradesh" ["pincode"]=> string(6) "190010" ["country"]=> string(5) "India" ["phone1"]=> string(10) "9039180419" ["phone2"]=> string(10) "7681559402" ["email"]=> string(24) "educianstudent@gmail.com" ["is_sms_enabled"]=> string(3) "Yes" ["is_active"]=> int(1) ["has_finished"]=> int(0) ["student_category"]=> string(1) "5" ["course"]=> string(24) "58131c7099fbad4c1d0001c2" ["Biometric_ID"]=> string(1) "1" ["siblings"]=> string(14) "Cynthia Taylor" ["guardian_name"]=> string(14) "Cynthia Taylor" ["guardian_occupation"]=> string(13) "Senior Editor" ["guardian_qualification"]=> string(20) "Research Assistant I" ["guardian_email_id"]=> string(23) "educianparent@gmail.com" ["gaurdain_contact_details"]=> string(10) "9419513603" ["guardian_relationship"]=> string(6) "Father" ["height"]=> string(3) "4.9" ["weight"]=> string(4) "34.9" ["allergies"]=> string(0) "" ["batch"]=> int(2) ["academicyear"]=> string(4) "2015" ["batchhistory"]=> array(1) { [0]=> array(5) { ["batchid"]=> float(2) ["academic_year"]=> string(4) "2015" ["course"]=> string(24) "58131c7099fbad4c1d0001c2" ["sequenceno"]=> int(1) ["courseId"]=> object(MongoId)#24 (1) { ["$id"]=> string(24) "58131c7099fbad4c1d0001c2" } } } ["uploads"]=> array(1) { ["profile_pic"]=> string(39) "58131c7799fbad4c1d000202schoolgirl2.jpg" } ["created_at"]=> NULL ["updated_at"]=> string(0) "" ["routearray"]=> array(2) { [0]=> array(5) { ["routeid"]=> int(2) ["academicyear"]=> string(4) "2016" ["current"]=> int(0) ["vehicleno"]=> string(9) "JK01S8764" ["dateofassignment"]=> string(10) "09/28/2016" } [1]=> array(5) { ["routeid"]=> int(3) ["academicyear"]=> string(4) "2016" ["current"]=> int(1) ["vehicleno"]=> string(9) "JK01S8764" ["dateofassignment"]=> string(10) "11/17/2016" } } ["HostelAlloted"]=> array(7) { ["Food Preferences"]=> string(4) "Both" ["Hostel"]=> object(MongoId)#25 (1) { ["$id"]=> string(24) "58138aee99fbade41e000031" } ["Floor"]=> string(7) "Floor_1" ["RoomNumber"]=> int(11) ["Approved"]=> string(3) "yes" ["Approved On"]=> object(MongoDate)#26 (2) { ["sec"]=> int(1472322600) ["usec"]=> int(0) } ["Academic Year"]=> string(4) "2016" } ["HostelAllotmentHistory"]=> array(1) { [0]=> array(7) { ["Food Preferences"]=> string(4) "Both" ["Hostel"]=> object(MongoId)#27 (1) { ["$id"]=> string(24) "58138aee99fbade41e000031" } ["Floor"]=> string(7) "Floor_1" ["RoomNumber"]=> int(11) ["Approved"]=> string(3) "yes" ["Approved On"]=> object(MongoDate)#28 (2) { ["sec"]=> int(1472322600) ["usec"]=> int(0) } ["Academic Year"]=> string(4) "2016" } } ["courseId"]=> object(MongoId)#29 (1) { ["$id"]=> string(24) "58131c7099fbad4c1d0001c2" } } }
       ...
       ...                  
       }

我已经编写了以下函数来根据$ key中给出的键值对这些学生进行排序，以便数组在top / first中包含类似的结果。

       $sortedarray = array();
               $sortedarray = $this->multiSort(
                 $arraytosort,
                 $key,
                'fullname',
                'firstmiddle',
                'firstlast',
                'first_name',
                'middle_name',
                'last_name',
                'roll_no',
                'email'
                );

   function multiSort()
   { 
     $args = func_get_args(); 
     $c = count($args); 
     if ($c < 2) { 
          return false; 
     }

     $key= $args[1]; 

      $array = array_splice($args, 0, 1); 
      $array = $array[0];

      usort($array, function($a) use($args) { 

      $i = 0; 
      $c = count($args); 
      $cmp = 0; 
    while($cmp == 0 && $i < $c) 
    { 
        $cmp = stripos($a[$args[$i] ],$key); 
        $i++; 
    } 

    return $cmp; 
   }); 

   return $array; 
    } 

它抛出错误消息＆＃34;未定义的变量：key＆＃34;。 请帮忙!!!