calculating sum in objects

Question

I am in need to do this thing: I have an object like below, but i am in need to do the sum of the numbers of objects like object1_(anything), object2_(anything)

stdClass Object
(
    [object1_2012_06_12] => 16
    [object2_2012_06_12] => 10
    [object1_2012_06_11] => 16
    [object2_2012_06_11] => 10
)

For examaple: sum of object1_(anything) will be (object1_2012_06_12 + object1_2012_06_11) = (16+16)=32

Sorry for been unconstructive here but I would strongly recommend you change that design to an array of objects. It doesn't sit well with OOP — Luc
– Luc, Commented Jun 12, 2012 at 12:53
No it doesn't Mohan, it means your design makes it more complicated than it need be, not impossible — Mark Baker
– Mark Baker, Commented Jun 12, 2012 at 12:56

flowfree · Accepted Answer · 2012-06-12 12:52:33Z

8

You can cast your object to array:

$sum = 0;
foreach ((array)$myobj as $v) {
  $sum += intval($v);
}

Or as suggested by @MarkBaker:

$sum = array_sum((array)$myobj);

answered Jun 12, 2012 at 12:52

flowfree

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5 Comments

Thompson Over a year ago

I don't want to cast, i just want sum.

Mark Baker Over a year ago

isn't $sum = array_sum((array) $myobj); even easier?

flowfree Over a year ago

@MarkBaker man, I've been coding PHP for years and I missed that function. Thanks!

Thompson Over a year ago

I have converted the object to array, but don't know how can I do the sum of [array_val_1_2012_06_12] => 16 and [array_val_1_2012_06_11] => 16. dates are dynamically generated. Is there any wildcard as we use in sql like %

Marcus Recck Over a year ago

Yea, it's called regular expressions.

Ja͢ck · Accepted Answer · 2012-06-12 13:11:14Z

0

Just go through the object attributes and sum based on part before first underscore using strtok:

$sums = array();
foreach ($my_object as $key => $value) {
    $key = strtok($key, '_');

    if (!isset($sums[$key])) {
            $sums[$key] = $value;
    } else {
            $sums[$key] += $value;
    }
}

print_r($sums);

Or:

function sum_of_object_starting_with($my_object, $starts_with)
{
    $sum = 0; $prefix_len = strlen($starts_with);
    foreach ($my_object as $key => $value) {
        if (strncmp($key, $starts_with, $prefix_len)) {
            $sum += $value;
        }
    }
    return $sum;
}

print_r(sum_of_object_starting_with($my_object, 'object1_'));

edited Jun 12, 2012 at 13:11

answered Jun 12, 2012 at 13:05

Ja͢ck

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Comments

DaveRandom · Accepted Answer · 2012-06-12 13:27:05Z

0

This code will get the value you want:

function sum_by_object_name ($data, $objName) {

  // Temporary array to hold values for a object name
  $objValues = array();

  // Convert input object to array and iterate over it
  foreach ((array) $data as $key => $val) {

    // Extract the object name portion of the key
    $keyName = implode('_', array_slice(explode('_', $key), 0, -3));

    // If object name is correct push this value onto the temp array
    if ($keyName == $objName) {
      $objValues[] = $val;
    }

  }

  // Return the sum of the temp array
  return array_sum($objValues);

}

// Calculate the total of $object
$total = sum_by_object_name($object, 'object1');

See it working

edited Jun 12, 2012 at 13:27

answered Jun 12, 2012 at 13:12

DaveRandom

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