Online PHP editor | output for 9tsVd

<?php function array_partition($array, $callback, $recursive = true) { $ret = array (); $walk = ($recursive) ? 'array_walk_recursive' : 'array_walk'; $walk ( $array, function ($value, $key) use($callback, &$ret) { $index = call_user_func_array ( $callback, array ( $value, $key ) ); if (isset ( $ret [$index] )) $ret [$index] [] = $value; else $ret [$index] = array ( $value ); } ); return $ret; } $p1 = (object) array('a'=>1,'b'=>2); $p2 = (object) array('a'=>1,'b'=>3); $p3 = (object) array('a'=>2,'b'=>4); $posts[] = $p1; $posts[] = $p2; $posts[] = $p3; $posts = array_partition($posts, function ($post, $i) { return $post->a; }, false); print_r($posts); ?>