I have the array shown below. I would like to have a resultant array where value in the key elements [tv], [tu], [cost], [km] are summed for all the row with same value of [tick_id]. In this example we should sum the value [tv], [tu], [cost], [km] of the array elements 0, 1, 2, … How can I do this?

Array (
    [0] => stdClass Object (
        [id] => 15
        [user_id] => 44
        [name] => inspector1
        [tv] => 0.00
        [tc] => 0.00
        [tu] => 0.00
        [cost] => 0.00
        [kms] => 0
        [date_s] => 2012-03-30
        [notes] =>
        [tick_id] => 11
        [tot_fee] => 5500
    )
    [1] => stdClass Object (
        [id] => 39
        [user_id] => 46
        [name] => Assistant
        [tv] => 10.00
        [tc] => 0.00
        [tu] => 4.50
        [cost] => 0.00
        [kms] => 120
        [date_s] => 2012-03-31
        [notes] =>
        [tick_id] => 15
        [tot_fee] => 0
     )
    [2] => stdClass Object (
        [id] => 35
        [user_id] => 46
        [name] =>
        [tv] => 0.00
        [tc] => 0.00
        [tu] => 0.00
        [cost] => 0.00
        [kms] => 0
        [date_s] => 2012-03-30
        [notes] =>
        [tick_id] => 13
        [tot_fee] => 3200
    )
    …
)

• php
• arrays

It's hard to tell with the way your code is displaying but this should be what you need:

// Create the cost total array
$cost = array();

// Iterate over each object in the given array
foreach ($array as $object)
{

  // If the tick_id has not yet been assigned as a key then do so with a default cost of 0
  if (!isset($cost[$object->tick_id]))
  {
    $cost[$object->tick_id] = 0;
  }

  // Increment the total cost for the given tick_id
  $cost[$object->tick_id] += $object->tv + $object->km + $object->tu + $object->cost;

}

$cost will be an array where the key is the tick_id and the value is the total cost.