Grouping PHP Array on 2 or more different values -

i'm creating recent activity section , trying group similar items. want able group activities based on type of activity , did activity. instance:

array (     [0] => array         (             [user] => bill             [type] => photo             [id] => 1             [timestamp] => 12345678         )      [1] => array         (             [user] => joe             [type] => photo             [id] => 2             [timestamp] => 12345678         )      [2] => array         (             [user] => bill             [type] => comment             [id] => 1             [timestamp] => 12345678         )      [3] => array         (             [user] => bill             [type] => photo             [id] => 3             [timestamp] => 12345678         )  ) 

could turn this:

array (     [0] => array         (             [user] => bill             [type] => photo             [items] => array                 (                     [0] => array                         (                             [id] => 1                             [timestamp] => 12345678                         )                      [1] => array                         (                             [id] => 3                             [timestamp] => 12345678                         )                  )          )      [1] => array         (             [user] => joe             [type] => photo             [items] => array                 (                     [0] => array                         (                             [id] => 2                             [timestamp] => 12345678                         )                  )          )      [2] => array         (             [user] => bill             [type] => comment             [items] => array                 (                     [0] => array                         (                             [id] => 1                             [timestamp] => 12345678                         )                  )          )  ) 

this trying not quite there: grouping arrays in php

anyone have idea?

your grouping doesn't make sense (it makes little more sense after edit), try this:

foreach ($activity $data) {    $newdata[$data['user']][$data['type']]['id'][]=$data['id'];    $newdata[$data['user']][$data['type']]['timestamp'][]=$data['timestamp']; } 

edit reflect changes in desired output: (and structure bit more useful)

foreach ($activity $data) {     $newdata[$data['user']][$data['type']]['items'][]=array('id'=>$data['id'],'timestamp'=>$data['timestamp']); }   

edit 2:

you have have sort of key, in case combo of username , type. have re-index numeric if matters. should quite close want:

foreach ($activity $data) {         $key=$data['user'].'-'.$data['type'];         $newdata[$key]['items'][]=array('id'=>$data['id'],'timestamp'=>$data['timestamp']);         $newdata[$key]['user']=$data['user'];         $newdata[$key]['type']=$data['type']; } $newdata=array_values($newdata); 

tested:
http://www.ideone.com/3uzdd

edit 3:

separate dates... idea started, you'll need little more original array this.

foreach ($activity $data) {         $key=$data['user'].'-'.$data['type'];         $newdata[$key]['items'][$data['day']][]=array('id'=>$data['id'],'timestamp'=>$data['timestamp']);         $newdata[$key]['user']=$data['user'];         $newdata[$key]['type']=$data['type']; } $newdata=array_values($newdata);