How to update specific key's value in an associative array in PHP? -

i've following associative array named $data

array (     [0] => array         (             [transaction_user_id] => 359691e27b23f8ef3f8e1c50315cd506             [transaction_no] => 19500912050218             [transaction_total_amount] => 589.00             [transaction_date] => 1335932419             [transaction_status] => cancelled         )      [1] => array         (             [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d             [transaction_no] => 36010512050819             [transaction_total_amount] => 79.00             [transaction_date] => 1336476696             [transaction_status] => cancelled         )      [2] => array         (             [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d             [transaction_no] => 19020512050820             [transaction_total_amount] => 299.00             [transaction_date] => 1336476739             [transaction_status] => cancelled         )      [3] => array         (             [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d             [transaction_no] => 27050512050821             [transaction_total_amount] => 79.00             [transaction_date] => 1336476927             [transaction_status] => cancelled         )      [4] => array         (             [transaction_user_id] => 8e9050a3646c98342b9ba079fba80982             [transaction_no] => 12070512050822             [transaction_total_amount] => 129.00             [transaction_date] => 1336477032             [transaction_status] => cancelled         )  ) 

and want convert value of key [transaction_date] user readable format (i.e. mm/dd/yyyy). written following code in function returns whole array:

 foreach($data $value)         {             $value[transaction_date]=date('d/m/y',$value[transaction_date]);         }      return $data; 

my problem i'm getting same array without changing value of [transaction_date] array elements. array updated values [transaction_date] expected returned. can me out resolve issue? in advance.

change foreach this, not assigning data return variable $data after performing operation on that.

foreach($data $key => $value) {   $data[$key]['transaction_date'] = date('d/m/y',$value['transaction_date']); } 

codepad demo.