sum value in foreach loop based on another value php - php

Question

I have an array like below. There are id, label, cost, and cid in an array. We want to sum the cost based on the cid like for cid 22 cost should be 196.5 and for cid 11 cost should be 44.4. In our out put array we want to keep the label, cost (sum), and cid, Please see expected output array.
Array
(
[0] => Array
(
[id] => 1331
[label] => PM1
[cost] => 98.25
[cid] => 22
[product_id] => 133
)
[1] => Array
(
[id] => 1332
[label] => PM3
[cost] => 22.20
[cid] => 11
[product_id] => 133
)
[2] => Array
(
[id] => 1341
[label] => PM1
[cost] => 98.25
[cid] => 22
[product_id] => 134
)
[3] => Array
(
[id] => 1342
[label] => PM3
[cost] => 22.20
[cid] => 11
[product_id] => 134
)
)
Tried below
foreach ($array $key => $value) {
$final[$value['cid']] += $value['cost'];
}
print_r ($final);
Getting below as an output
Array
(
[22] => 196.5
[11] => 44.4
)
Want expected output like below.
Array
(
[22] => Array
(
[label] => PM1
[cost] => 196.5
[cid] => 22
)
[11] => Array
(
[label] => PM3
[cost] => 44.4
[cid] => 11
)
)
Basically want to sum cost based on cid and want to keep the label, cost (sum), and cid.
Any help will be greatly appreciated.

Answer 1

I believe this should do the trick
$CIDs_identified = array();
$final_array = array();
foreach($original_array as $small_array){
if(!in_array($small_array['cid'], $CIDs_identified)){
$CIDs_identified[] = $small_array['cid'];
$final_array[$small_array['cid']] = array(
'label' => $small_array['label'],
'cost' => $small_array['cost'],
'cid' => $small_array['cid'],
);
}else{
$final_array[$small_array['cid']]['cost'] += $small_array['cost'];
}
}

Answer 2

On this site, if you can provide your source array in usable format, that is really helpful so that we don't have to retype it. One way to do that is using var_export.
Below is a simple version. Create an array indexed by cid. If that item doesn't exist, populate it with the basic data and a zero cost. Then on each loop, including the initial, add the row's cost.
<?php
$data = [
[
'id' => 1331,
'label' => 'PMI',
'cost' => 98.25,
'cid' => 22,
'product_id' => 133,
],
[
'id' => 1341,
'label' => 'PMI',
'cost' => 98.25,
'cid' => 22,
'product_id' => 134,
],
];
$output = [];
foreach ($data as $item) {
if (!isset($output[$item['cid']])) {
$output[$item['cid']] = [
'label' => $item['label'],
'cost' => 0,
'cid' => $item['cid'],
];
}
$output[$item['cid']]['cost'] += $item['cost'];
}
print_r($output);
Demo here: https://3v4l.org/MY6Xu

Answer 3

$list = [
[ 'id' => 1331, 'label' => 'PM1', 'cost' => 98.25, 'cid' => 22, 'product_id' => 133 ],
[ 'id' => 1332, 'label' => 'PM3', 'cost' => 22.20, 'cid' => 11, 'product_id' => 133 ],
[ 'id' => 1341, 'label' => 'PM1', 'cost' => 98.25, 'cid' => 22, 'product_id' => 134 ],
[ 'id' => 1342, 'label' => 'PM3', 'cost' => 22.20, 'cid' => 11, 'product_id' => 134 ]
];
$result = [];
array_walk($list, function ($item) use (&$result) {
if (isset($result[$item['cid']])) {
$result[$item['cid']]['cost'] = $item['cost'] + $result[$item['cid']]['cost'];
} else {
$result[$item['cid']] = [ 'label' => $item['label'], 'cost' => $item['cost'], 'cid' => $item['cid'] ];
}
});
print_r($result);
Output:
Array
(
[22] => Array
(
[label] => PM1
[cost] => 196.5
[cid] => 22
)
[11] => Array
(
[label] => PM3
[cost] => 44.4
[cid] => 11
)
)