PHP add values from two arrays - php

Question

I have two php arrays that are in different orders. I want to find the correct array from array one and array two and add them together based on the values from currency, itemsSold and total. I also need to group them by currency and PaymentType.
First Array
array (
0 =>
array (
'currency' => 'USD',
'department' => 'Mens',
'itemsSold' => 4566,
'paymentType' => 'Cash;Card;Voucher',
'total' => 4800,
),
1 =>
array (
'currency' => 'USD',
'department' => 'womens',
'itemsSold' => 6221,
'paymentType' => 'Cash;Card;Voucher',
'total' => 9888,
),
2 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 20,
'paymentType' => 'Cash;Card;Voucher',
'total' => 17233,
),
3 =>
array (
'currency' => 'GBP',
'department' => 'Home',
'itemsSold' => 20,
'paymentType' => 'Voucher',
'total' => 677,
),
4 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 20,
'paymentType' => 'Voucher',
'total' => 17233,
)
)
Second Array
array (
0 =>
array (
'currency' => 'USD',
'department' => 'Mens',
'itemsSold' => 12,
'paymentType' => 'Cash;Card;Voucher',
'total' => 11,
),
1 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 20,
'paymentType' => 'Cash;Card;Voucher',
'total' => 500,
),
2 =>
array (
'currency' => 'USD',
'department' => 'womens',
'itemsSold' => 8,
'paymentType' => 'Cash;Card;Voucher',
'total' => 1277,
),
3 =>
array (
'currency' => 'GBP',
'department' => 'Home',
'itemsSold' => 20,
'paymentType' => 'Voucher',
'total' => 677,
),
4 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 40,
'paymentType' => 'Voucher',
'total' => 17233,
)
)
Desired Array
array (
0 =>
array (
'currency' => 'USD',
'department' => 'Mens',
'itemsSold' => 4578,
'paymentType' => 'Cash;Card;Voucher',
'total' => 4811,
),
1 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 40,
'paymentType' => 'Cash;Card;Voucher',
'total' => 1856,
),
2 =>
array (
'currency' => 'USD',
'department' => 'womens',
'itemsSold' => 6229,
'paymentType' => 'Cash;Card;Voucher',
'total' => 11165,
),
3 =>
array (
'currency' => 'GBP',
'department' => 'Home',
'itemsSold' => 40,
'paymentType' => 'Voucher',
'total' => 1354,
),
4 =>
array (
'currency' => 'USD',
'department' => 'Home',
'itemsSold' => 60,
'paymentType' => 'Voucher',
'total' => 34466,
)
As you can see, the values have been added together to give the total in a new array.
I have tried array_merge() but that just adds the arrays in each-other so the desired array is 6 items long, it doesn't add the values of the arrays together.
I tried looping foreach though first array and then using the index to find the items in the second array but the index changes as the arrays can be in any order.
I'm very new to programming and especially PHP, so I would appreciate a detailed answer that helps me learn it.
Thanks

Answer 1

Short version of code, $a1 and $a2 are your arrays:
$newarray = [];
// rebuild array so as key is unique value,
// in your case it is 'department':
foreach ($a1 as $item) {
$newarray[$item['department']] = $item;
// Or if you group by both currency and department:
$key = $item['department'] . $item['currency'];
$newarray[$key] = $item;
}
foreach ($a2 as $item) {
$department = $item['department'];
if (isset($newarray[$department])) {
$newarray[$department]['itemsSold'] += $item['itemsSold'];
$newarray[$department]['total'] += $item['total'];
}
// Or if you group by both currency and department:
$key = $item['department'] . $item['currency'];
if (isset($newarray[$key])) {
$newarray[$key]['itemsSold'] += $item['itemsSold'];
$newarray[$key]['total'] += $item['total'];
}
}
$newarray = array_values($newarray);
print_r($newarray);
Full fiddle here.