Online PHP editor | output for TXJjt

<?php $myarray = array( [ 'messageId' => '5ACE9D8841', 'sender' => 'john@doe.com', ], [ 'messageId' => '7EE67D8170', 'sender' => 'dan@doe.com', ], [ 'messageId' => '8095FD8836', 'sender' => 'cat@doe.com', ], [ 'messageId' => ['brokenId' => '8095FD8836'], 'sender' => 'cat@doe.com', ], [ 'status' => 'wrong row', ], [ 'messageId' => '7EE67D8170', 'dest' => 'mitch@doe.com', 'status' => 'sent', 'date' => '2021-02-01 11:06:55', ], ); $result = array_reduce($myarray, function($rows, $item){ if (array_key_exists('messageId', $item) && is_scalar($item['messageId'])) { $rows = array_replace_recursive($rows ?? [], [$item['messageId'] => $item]); } return $rows; }); $result = array_values($result); print_r($result);