数组排序吗？

classify.php

<?php
class Classify {
  public $idKey = '';
	public $parentIdKey = '';
	
	/**
	 *
	 * @param string $formatStr        	
	 */
	public function __construct() {
	}
	/**
	 *
	 * @param array $rows        	
	 * @param int $parent_id        	
	 * @return NULL,array
	 */
	public function classify($array, $parent_id = 0) {
		$childs = $this->findChild ( $array, $parent_id );
		if (empty ( $childs )) {
			return null;
		}
		foreach ( $childs as $k => $v ) {
			$rescurTree = $this->classify ( $array, $v [$this->idKey] );
			if (null != $rescurTree) {
				$childs [$k] ['childs'] = $rescurTree;
			}
		}
		return $childs;
	}
	/**
	 *
	 * @param array $arr        	
	 * @param int $id        	
	 * @return NULL,array
	 */
	protected function findChild(&$array, $id) {
		$childs = array ();
		foreach ( $array as $k => $v ) {
			if ($v [$this->parentIdKey] == $id) {
				$childs [] = $v;
			}
		}
		return $childs;
	}
}