php - Extracting a specific part of a string -

i have string:

[25-03-15, 1236], [26-03-15, 3000], [27-03-15, 3054], [30-03-15, 4000] 

i want 2 parts below:

['25-03-15','26-03-15','27-03-15','30-03-2015'] 

and

[1236,3000,3054,4000] 

please guide me how can perform task.

ps: working of view page of codeigniter.

i'm getting first thing as:

<?php  $usd=$this->db->query('select transaction_date, sum(amount) total  transactions group transaction_date')->result_array(); $str = '';  for($i=0; $i<count($usd); $i++){     if($i!=0){         $str = $str.', ['.date('d-m-y', strtotime($usd[$i]["transaction_date"])).', '.$usd[$i]["total"].']';     }else{         $str = $str.'['.date('d-m-y', strtotime($usd[$i]["transaction_date"])).', '.$usd[$i]["total"].']';     } }  echo $str;  ?> 

try this..

  $date = '';   $total = ''; for($i=0; $i<count($usd); $i++){     if($i!=0){         $date .= date('d-m-y', strtotime($usd[$i]["transaction_date"])).', ';          $total .= $usd[$i]["total"].', ';      }else{          $date .= date('d-m-y', strtotime($usd[$i]["transaction_date"])).', ';          $total .= $usd[$i]["total"].', ';     } }   echo $finaldate='['. $date.']';   echo $finaltotal='['. $total.']';