PHP Loop - Sum the Value of an Array if the Key Exists - php

Question

I have a multidimensional associative array that I need to loop through and collect the product specific data. Please see below:
$rawData = array(
array(
'sku' => 'product1',
'quantity' => '3'
),
array(
'sku' => 'product2',
'quantity' => '3'
),
array(
'sku' => 'product1',
'quantity' => '2'
)
);
$collectedData = array();
for ($i = 0; $i < count($rawData); $i++) {
$collectedData += array($rawData[$i]['sku'] => $rawData[$i]['quantity']);
}
print_r($collectedData);
This outputs the following:
Array
(
[product1] => 3
[product2] => 3
)
What I need however is that if the array key sku already exists in the $collectedData array, for the quantity of the array value to be added to the already existing quantity.
So this would be my desired result (as product1 exists twice with values 2 and 3):
Array
(
[product1] => 5
[product2] => 3
)
Is there an easy way of doing this? Thank you very much for any help in advance.

Answer 1

Simply check key is available or not. if avalable then sum quantity
$rawData = array(
array(
'sku' => 'product1',
'quantity' => '3'
),
array(
'sku' => 'product2',
'quantity' => '3'
),
array(
'sku' => 'product1',
'quantity' => '2'
)
);
$collectedData = array();
for ($i = 0; $i < count($rawData); $i++) {
if(isset($collectedData[$rawData[$i]['sku']]))
$collectedData[$rawData[$i]['sku']] += $rawData[$i]['quantity'];
else
$collectedData += array($rawData[$i]['sku'] => $rawData[$i]['quantity']);
}
print_r($collectedData);
Also I suggest you foreach loop for simplification and unneccessary use of indexes
$collectedData = array();
foreach($rawData as $row){
if(isset($collectedData[$row['sku']]))
$collectedData[$row['sku']] += $row['quantity'];
else
$collectedData += array($row['sku'] => $row['quantity']);
}
print_r($collectedData);
DEMO

Answer 2

Lop the array with foreach, and check if the key exists - if it doesn't, set the value to the quantity, if it does, add it to the existing quantity. The key represents the product. We check if its set or not to avoid having the code produce warnings (as you can see this demo produces).
$collectedData = array();
foreach ($rawData as $value) {
if (!isset($collectedData[$value['sku']]))
$collectedData[$value['sku']] = $value['quantity'];
else
$collectedData[$value['sku']] += $value['quantity'];
}
Live demo

Answer 3

$collectedData = array();
foreach($rawData as $data)
{
// if already exist then add
if(isset($collectedData[$data['sku']]))
{
$collectedData[$data['sku']] += $data['quantity'];
}
// else set value
else
{
$collectedData[$data['sku']] = $data['quantity'];
}
}
print_r($collectedData);