👀 Views: 61 💬 Answers: 1 📅 Created: 2025-07-03

php array callback PHP

I'm attempting to set up I'm trying to implement I'm working with an scenario with PHP 8.1 where the `array_reduce` function is not returning the expected results when applied to an associative array with a custom callback. My goal is to sum up values based on specific keys within the associative array, but it seems like the callback is not processing the values correctly. Here’s the code I’m using: ```php $data = [ ['category' => 'fruit', 'amount' => 10], ['category' => 'fruit', 'amount' => 20], ['category' => 'vegetable', 'amount' => 15], ['category' => 'fruit', 'amount' => 5], ['category' => 'vegetable', 'amount' => 10] ]; $result = array_reduce($data, function ($carry, $item) { if (!isset($carry[$item['category']])) { $carry[$item['category']] = 0; } $carry[$item['category']] += $item['amount']; return $carry; }, []); print_r($result); ``` This should ideally return an associative array like this: ```php [ 'fruit' => 35, 'vegetable' => 25 ] ``` However, I'm seeing an empty array as output: ```php Array ( ) ``` I've verified that `$data` is correctly structured, and I believe the callback logic is sound. I even checked for typos or syntax errors but found none. What am I missing here? Is there something in the usage of `array_reduce` that I might have overlooked? Any insights would be greatly appreciated! The project is a CLI tool built with Php. I appreciate any insights! I'm on macOS using the latest version of Php. Has anyone else encountered this?