Online PHP editor | refs for 7hEGN

<?php $array = [ 'a' => ['id' => 20, 'name' => 'chimpanzee'], 'b' => ['id' => 40, 'name' => 'meeting'], 'c' => ['id' => 20, 'name' => 'dynasty'], 'd' => ['id' => 50, 'name' => 'chocolate'], 'e' => ['id' => 10, 'name' => 'bananas'], 'f' => ['id' => 50, 'name' => 'fantasy'], 'g' => ['id' => 50, 'name' => 'football'] ]; asort($array); var_export( array_reduce( array_keys($array), function($result, $k) use ($array) { $result[$array[$k]['id']][$k] = $array[$k]; return $result; } ) );