- print_r: documentation ( source)
- array_values: documentation ( source)
<?php
$array = array(
array('delivery_plan' => '80::2020/07', 'additional_amount_usd' => 32.88),
array('delivery_plan' => '80::2020/09', 'additional_amount_usd' => 16.44),
array('delivery_plan' => '80::2020/07', 'additional_amount_usd' => 32.88),
);
$sum_array = [];
foreach ($array as $item) {
if (!isset($sum_array[$item['delivery_plan']])) { // initialization
$sum_array[$item['delivery_plan']] = ['delivery_plan' => $item['delivery_plan'], 'additional_amount_usd' => 0.0];
}
$sum_array[$item['delivery_plan']]['additional_amount_usd'] += $item['additional_amount_usd'];
}
$sum_array = array_values($sum_array);
print_r($sum_array);