Sum values by two matching keys in multidimensional arrays in PHP - php

Question

I have a multidimensional array that has a date, name, & markup.
$in = [
[
'saledate' => '2016-02-01',
'name' => 'John Doe',
'markup' => 561
],
[
'saledate' => '2016-02-01',
'name' => 'John Doe',
'markup' => 681
],
[
'saledate' => '2016-02-02',
'name' => 'John Doe',
'markup' => 379
],
[
'saledate' => '2016-02-01',
'name' => 'Jane Doe',
'markup' => 205
],
[
'saledate' => '2016-02-02',
'name' => 'Jane Doe',
'markup' => 900
],
[
'saledate' => '2016-02-02',
'name' => 'Jane Doe',
'markup' => 787
],
[
'saledate' => '2016-02-03',
'name' => 'Jane Doe',
'markup' => 211
]
]
I'm trying to sum the values for each person by date for the desired output:
0 =>
array (size=3)
'name' => string 'John Doe' (length=8)
'2016-02-01' => float 1242
'2016-02-02' => float 379
1 =>
array (size=3)
'name' => string 'Jane Doe' (length=8)
'2016-02-01' => float 205
'2016-02-02' => float 1687
'2016-02-03' => float 211
Here is what I have but I think I'm just confusing myself...
$out = array();
foreach ($in as $row)
{
$result[$row['saledate']]['saledate'] = $row['saledate'];
$result[$row['name']]['name'] = $row['name'];
$result[$row['date']]['markup'] += $row['markup'];
}
$out = array_values($out);

Answer 1

Store the name as the key in your output array, it'll make grouping the results easier:
$out = array();
foreach ($in as $row) {
/* set the key using the name, eg. $out['John Doe'] */
if (! isset($out[$row['name']])) {
$out[$row['name']] = array('name' => $row['name']);
}
/* if the saledate isn't already exist, set it */
if (! isset($out[$row['name']][$row['saledate']])) {
$out[$row['name']][$row['saledate']] = 0;
}
/* add the markup */
$out[$row['name']][$row['saledate']] += $row['markup'];
}
Which would give you:
Array
(
[John Doe] => Array
(
[name] => John Doe
[2016-02-01] => 1242
[2016-02-02] => 379
)
[Jane Doe] => Array
(
[name] => Jane Doe
[2016-02-01] => 205
[2016-02-02] => 1687
[2016-02-03] => 211
)
)
If you don't want the name key, just use $out = array_values($out).

Answer 2

Try this code:
$result = array();
array_walk(
$in,
function ($row) use (&$result) {
$key = array_search($row['name'], array_column($result, 'name'));
if ($key === False) {
$key = array_push($result, array('name' => $row['name'])) - 1;
}
$date = $row['saledate'];
if (!isset($result[$key][$date]))
$result[$key][$date] = $row['markup'];
else
$result[$key][$date] += $row['markup'];
}
,
$result
);
print_r($result);
3v4l.org demo
After init an empty array, we pass it by reference as second arguments to array_walk: inside the called function, we check if the name and date already exists: if it is, we add the current value, otherwise we create new element(s) with current value.
See more about array_walk()
See more about array_column() PHP > 5.5
See more about passing by reference

Answer 3

Assigning temporary first level keys to the result array can be avoided by pushing reference variables into the result array then manipulating only the references as needed.
Code: (Demo)
$result = [];
foreach ($in as ['saledate' => $s, 'name' => $n, 'markup' => $m]) {
if (!isset($ref[$n])) {
$ref[$n] = ['name' => $n, $s => $m];
$result[] = &$ref[$n];
} else {
$ref[$n][$s] = ($ref[$n][$s] ?? 0) + $m;
}
}
var_export($result);