Online PHP editor | refs for M8Vs8

<?php $arr = array( "artists" => array( "1" => array( "id" => "1", "firstname" => "John", "lastname" => "Doe", "songs" => array( array("name" => "song_1", "year" => "1999"), array("name" => "song_2", "year" => "1987") ), ), "2" => array( "id" => "2", "firstname" => "Jane", "lastname" => "Doe", "songs" => array( array("name" => "song_1", "year" => "2000"), array("name" => "song_2", "year" => "1999") ) ), "3" => array( "id" => "3", "firstname" => "Mark", "lastname" => "Doe", "songs" => array( array("name" => "song_1", "year" => "1984"), array("name" => "song_2", "year" => "1983") ) ) ) ); array_walk($arr['artists'], function (&$song) { usort($song['songs'], function ($a, $b) { return $a['year'] > $b['year'] ? 1 : -1; }); // Ascending order //usort($song['songs'], function ($a, $b) { return $a['year'] < $b['year'] ? 1 : -1; }); // Descending order }); print('<pre>'); print_r($arr); print('</pre>');