Group an array of objects by one column and sum another column within each group

Question

After merging two arrays of objects, I get an array structured like this. I would like to group objects with the same ID and add to their quantity

[
    {
        id  :   1
        nome    :   T.SHIRT
        quantita    :   2
    
    }, 
    {
        id  :   2
        nome    :   Sweatshirt
        quantita    :   4
    
    },
  {
        id  :   1
        nome    :   T.SHIRT
        quantita    :   4
    
    }
]

I would like to get an array like this.

[
    {
        id  :   1
        nome    :   T.SHIRT
        quantita    :   6
    
    }, 
  {
        id  :   2
        nome    :   Sweatshirt
        quantita    :   4
    
    },
]   

How can I do this?

Answer 1

The following logic might help you on your way: $store will contain the restructured array with cumulative 'quantita' per 'id'.

<?php
$arr = [
    (object)['id' => 1, 'nome' => 'T.SHIRT', 'quantita' => 2,],
    (object)['id' => 2, 'nome' => 'Sweatshirt', 'quantita' => 4,],
    (object)['id' => 1, 'nome' => 'T.SHIRT', 'quantita' => 4,],
];

$store = [];
foreach($arr as $record) {
    if(isset($store[$record->id])) {
        $store[$record->id]->quantita += $record->quantita;
    } else $store[$record->id] = $record;
}

working demo