PHP - array_map 2 columns and remove duplicate rows by key [duplicate] - php

Question

This question already has answers here:
Filter/Remove rows where column value is found more than once in a multidimensional array
(4 answers)
Closed 9 months ago.
I have the following array dynamically generated from an external API:
$purchases = array(
array('product_id' => 7, 'receipt' => R13D13),
array('product_id' => 5, 'receipt' => Y28Z14),
array('product_id' => 7, 'receipt' => R02310),
array('product_id' => 5, 'receipt' => E11403)
);
Desired output:
$purchases_new = array(
array('product_id' => 7, 'receipt' => R13D13),
array('product_id' => 5, 'receipt' => Y28Z14)
);
Due to the nature of the API I have only been able to pull data using array_map:
$purchases_unique = array_unique(
array_map(function($pid){ return $pid['product_id']; }, $purchases)
);
print_r($purchases_unique);
Outputs
array((array[251] => 7) array([252] => 5))
Output completely not what I want :( How to array_map 2 columns product_id' and receipt and remove duplicate rows based on product_id?
I want to achieve the following:
array_map both columns? (product_id and receipt)
Remove product_id duplicates rows based on product_id key?

Answer 1

If you want the first occurrence use #TheFirstBird answer. If you want the last occurrence you can do it simpler buy using array_column and array_values as:
$newArr = array_values(array_column($purchases, null, "product_id"));
Notice the second argument of array_column is null meaning take the entire element.
Live example: 3v4l
References: array-column, array-values

Answer 2

I think this will do what you're looking for:
Just adds the unique product_ids (with receipt) to a new array:
$purchases_new = array_reduce($purchases, function($acc, $p) {
if(!in_array($p['product_id'], array_column($acc, 'product_id'))) {
$acc[] = $p;
}
return $acc;
}, []);
Output:
array (
0 =>
array (
'product_id' => 7,
'receipt' => 'R13D13',
),
1 =>
array (
'product_id' => 5,
'receipt' => 'Y28Z14',
),
)
Try it online!

Answer 3

As per the comment It does not matter if it's the first or last occurrence, you could use a foreach and create a $result array for the non duplicates.
For every iteration, use the product_id as the array key and check if it already has been set.
If it is not, then add it.
$purchases = array(
array('product_id' => 7, 'receipt' => "R13D13"),
array('product_id' => 5, 'receipt' => "Y28Z14"),
array('product_id' => 7, 'receipt' => "R02310"),
array('product_id' => 5, 'receipt' => "E11403")
);
$result = [];
foreach($purchases as $key => $purchase) {
if (!isset($result[$purchase["product_id"]])) {
$result[$purchase["product_id"]] = $purchase;
}
}
print_r($result);
Result
Array
(
[7] => Array
(
[product_id] => 7
[receipt] => R13D13
)
[5] => Array
(
[product_id] => 5
[receipt] => Y28Z14
)
)
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