👀 Views: 77 💬 Answers: 1 📅 Created: 2025-08-06

php usort sorting arrays PHP

I'm trying to debug I'm encountering an issue while trying to sort a multidimensional array in PHP 8.1 using the `usort` function... I have an array of associative arrays representing users with attributes like 'name' and 'age'. My goal is to sort this array by age in ascending order, but the output is not as expected. Here's a simplified version of my code: ```php $users = [ ['name' => 'Alice', 'age' => 30], ['name' => 'Bob', 'age' => 25], ['name' => 'Charlie', 'age' => 35] ]; usort($users, function ($a, $b) { return $a['age'] <=> $b['age']; }); print_r($users); ``` After running this code, I expected the array to be sorted as follows: ```php [ ['name' => 'Bob', 'age' => 25], ['name' => 'Alice', 'age' => 30], ['name' => 'Charlie', 'age' => 35] ] ``` However, the output seems correct, but when I try to sort based on both 'age' and 'name' (to handle cases where ages are the same), I'm facing unexpected results. Here's my modified sort function: ```php usort($users, function ($a, $b) { if ($a['age'] === $b['age']) { return $a['name'] <=> $b['name']; } return $a['age'] <=> $b['age']; }); ``` I assumed this would sort the users first by age and then by name alphabetically if ages are the same. However, when adding another user with the same age: ```php $users[] = ['name' => 'David', 'age' => 30]; ``` The output was: ```php [ ['name' => 'Alice', 'age' => 30], ['name' => 'David', 'age' => 30], ['name' => 'Bob', 'age' => 25], ['name' => 'Charlie', 'age' => 35] ] ``` It seems to sort `Alice` before `David`, which is not what I want. I’ve double-checked my logic and it seems sound. Am I missing something in the comparison, or is there a better way to handle this situation? Any insights or alternative methods would be greatly appreciated! This is part of a larger API I'm building. My development environment is Ubuntu 22.04. Any ideas what could be causing this? I'm working on a CLI tool that needs to handle this. What are your experiences with this?