PHP: Sum values in a multidimensional array

To sum up all the values in a multidimensional array that live under a specific key we make use of two array functions.

First, we call the function array_column(), which returns to us an array of all the values found for a specific key.

Second, we use the method array_sum() to sum up all those values.

<?php

$products = [
    [
        'name' => 'Pen',
        'price' => 3,
    ],
    [
        'name' => 'Paper',
        'price' => 5,
    ],
];

$sum = array_sum(array_column($products, 'price'));
//=> 8