arrays - Grouping a php object -

i've php object outputs :

array (      [0] => stdclass object (          [id] => 25          [itemid] => 13          [studentid] => 9          [score] => 22          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst9          [lastname] => studentlast9     )      [1] => stdclass object (          [id] => 26          [itemid] => 13          [studentid] => 10          [score] => 23          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst10          [lastname] => studentlast10      )      [2] => stdclass object (          [id] => 1          [itemid] => 1          [studentid] => 1          [score] => 2          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )      [3] => stdclass object (          [id] => 2          [itemid] => 1          [studentid] => 2          [score] => 3          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )      [4] => stdclass object (          [id] => 9          [itemid] => 5          [studentid] => 1          [score] => 6          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )      [5] => stdclass object (          [id] => 10          [itemid] => 5          [studentid] => 2          [score] => 7          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )      [6] => stdclass object (          [id] => 17          [itemid] => 9          [studentid] => 1          [score] => 10          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )      [7] => stdclass object (          [id] => 18          [itemid] => 9          [studentid] => 2          [score] => 11          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )      [8] => stdclass object (          [id] => 3          [itemid] => 2          [studentid] => 1          [score] => 3          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )      [9] => stdclass object (          [id] => 4          [itemid] => 2          [studentid] => 2          [score] => 4          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )     [10] => stdclass object (          [id] => 11          [itemid] => 6          [studentid] => 1          [score] => 7          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1     )     [11] => stdclass object (          [id] => 12          [itemid] => 6          [studentid] => 2          [score] => 8          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )     [12] => stdclass object (          [id] => 19          [itemid] => 10          [studentid] => 1          [score] => 11          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )     [13] => stdclass object (          [id] => 20          [itemid] => 10          [studentid] => 2          [score] => 12          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      )     [14] => stdclass object (          [id] => 7          [itemid] => 4          [studentid] => 1          [score] => 5          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst1          [lastname] => studentlast1      )     [15] => stdclass object (          [id] => 8          [itemid] => 4          [studentid] => 2          [score] => 6          [imagealt] =>          [timemodified] => 0          [data] =>          [firstname] => studentfirst2          [lastname] => studentlast2      ) ) 

as, 1 can see, there 2 studentid having different itemid. want group them , print table like:

                  itemidid1    itemidid2   itemidid3 studentid1            x1          x2             x3 studentid2            y1          y2             y3 

i'm trying following code, displays values 1 below other.

<?php foreach ($hits $hit): ?>             <?php if ($hit->studentid == $current_id): ?>                 <td> <?php echo $hit->score; ?> </td>             <?php else: ?>                 <?php if ($current_id != -1): ?>                     </tr>                 <?php endif; ?>                 <?php $current_id = $hit->studentid; ?>                 <tr>                     <td><a href="#" id="<?php echo $hit->studentid; ?>" class="student-grade-data"> <?php echo $hit->firstname.' '.$hit->lastname; ?> </a></td>                     <td> <?php echo $hit->score; ?>                 </td>             <?php endif; ?>         <?php endforeach; ?> 

loop on objects , collect objects in 2 arrays like:

$bystudentid[$hit->studentid] = $hit; $byitemid[$hit->itemid] = $hit; 

then can columns array_keys($byitemid) , finaly build table looping on $bystudenid