	一句话概述代码的用途：（例：使用js控制复制及输入数据时只能是数字） 120* 字
	代码类型：无函数类插件单段代码直接可运行
	TAG标签：（用空格隔开） 30 字
	描述说明：请填写代码的实现原理、应用场景、功能说明、调用示例、注意事项等。
	无限分类都是采用递归的算法，但是我们知道递归即浪费时间，又浪费空间（内存），不用递归实现无限分类数据的树形格式化
	代码正文：*
	简单说明：排序： <?php /** * 5行代码实现无限分类数据的树形格式化 * http://my.oschina.net/u/918697 * @date 2012-12-12 / function genTree5($items) { foreach ($items as $item) $items[$item['pid']]['son'][$item['id']] = &$items[$item['id']]; return isset($items[0]['son']) ? $items[0]['son'] : array(); } /* * 将数据格式化成树形结构 9行代码实现无限分类数据的树形格式化 * @author Xuefen.Tong * @param array $items * @return array / function genTree9($items) { $tree = array(); //格式化好的树 foreach ($items as $item) if (isset($items[$item['pid']])) $items[$item['pid']]['son'][] = &$items[$item['id']]; else $tree[] = &$items[$item['id']]; return $tree; } $items = array( 1 => array('id' => 1, 'pid' => 0, 'name' => '江西省'), 2 => array('id' => 2, 'pid' => 0, 'name' => '黑龙江省'), 3 => array('id' => 3, 'pid' => 1, 'name' => '南昌市'), 4 => array('id' => 4, 'pid' => 2, 'name' => '哈尔滨市'), 5 => array('id' => 5, 'pid' => 2, 'name' => '鸡西市'), 6 => array('id' => 6, 'pid' => 4, 'name' => '香坊区'), 7 => array('id' => 7, 'pid' => 4, 'name' => '南岗区'), 8 => array('id' => 8, 'pid' => 6, 'name' => '和兴路'), 9 => array('id' => 9, 'pid' => 7, 'name' => '西大直街'), 10 => array('id' => 10, 'pid' => 8, 'name' => '东北林业大学'), 11 => array('id' => 11, 'pid' => 9, 'name' => '哈尔滨工业大学'), 12 => array('id' => 12, 'pid' => 8, 'name' => '哈尔滨师范大学'), 13 => array('id' => 13, 'pid' => 1, 'name' => '赣州市'), 14 => array('id' => 14, 'pid' => 13, 'name' => '赣县'), 15 => array('id' => 15, 'pid' => 13, 'name' => '于都县'), 16 => array('id' => 16, 'pid' => 14, 'name' => '茅店镇'), 17 => array('id' => 17, 'pid' => 14, 'name' => '大田乡'), 18 => array('id' => 18, 'pid' => 16, 'name' => '义源村'), 19 => array('id' => 19, 'pid' => 16, 'name' => '上坝村'), ); echo "<pre>"; print_r(genTree5($items)); print_r(genTree9($items)); //后者输出格式，前者类似，只是数组键值不一样，不过不影响数据结构 / Array ( [0] => Array ( [id] => 1 [pid] => 0 [name] => 江西省 [son] => Array ( [0] => Array ( [id] => 3 [pid] => 1 [name] => 南昌市 ) [1] => Array ( [id] => 13 [pid] => 1 [name] => 赣州市 [son] => Array ( [0] => Array ( [id] => 14 [pid] => 13 [name] => 赣县 [son] => Array ( [0] => Array ( [id] => 16 [pid] => 14 [name] => 茅店镇 [son] => Array ( [0] => Array ( [id] => 18 [pid] => 16 [name] => 义源村 ) [1] => Array ( [id] => 19 [pid] => 16 [name] => 上坝村 ) ) ) [1] => Array ( [id] => 17 [pid] => 14 [name] => 大田乡 ) ) ) [1] => Array ( [id] => 15 [pid] => 13 [name] => 于都县 ) ) ) ) ) [1] => Array ( [id] => 2 [pid] => 0 [name] => 黑龙江省 [son] => Array ( [0] => Array ( [id] => 4 [pid] => 2 [name] => 哈尔滨市 [son] => Array ( [0] => Array ( [id] => 6 [pid] => 4 [name] => 香坊区 [son] => Array ( [0] => Array ( [id] => 8 [pid] => 6 [name] => 和兴路 [son] => Array ( [0] => Array ( [id] => 10 [pid] => 8 [name] => 东北林业大学 ) [1] => Array ( [id] => 12 [pid] => 8 [name] => 哈尔滨师范大学 ) ) ) ) ) [1] => Array ( [id] => 7 [pid] => 4 [name] => 南岗区 [son] => Array ( [0] => Array ( [id] => 9 [pid] => 7 [name] => 西大直街 [son] => Array ( [0] => Array ( [id] => 11 [pid] => 9 [name] => 哈尔滨工业大学 ) ) ) ) ) ) ) [1] => Array ( [id] => 5 [pid] => 2 [name] => 鸡西市 ) ) ) )*/