9行代码，不用递归实现无限分类数据的树形格式化

http://www.oschina.net/code/snippet_173183_11767

 

<?php
/**
 * 将数据格式化成树形结构
 * @author Xuefen.Tong
 * @param array $items
 * @return array 
 */
function genTree($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;
}

$items = array(
    1 => array('id' => 1, 'pid' => 0, 'name' => '一级11'),
    2 => array('id' => 2, 'pid' => 1, 'name' => '二级21'),
    3 => array('id' => 3, 'pid' => 1, 'name' => '二级23'),
    4 => array('id' => 4, 'pid' => 9, 'name' => '三级31'),
    5 => array('id' => 5, 'pid' => 4, 'name' => '四级43'),
    6 => array('id' => 6, 'pid' => 9, 'name' => '三级32'),
    7 => array('id' => 7, 'pid' => 4, 'name' => '四级41'),
    8 => array('id' => 8, 'pid' => 4, 'name' => '四级42'),
    9 => array('id' => 9, 'pid' => 1, 'name' => '二级25'),
    10 => array('id' => 10, 'pid' => 11, 'name' => '二级22'),
    11 => array('id' => 11, 'pid' => 0, 'name' => '一级12'),
    12 => array('id' => 12, 'pid' => 11, 'name' => '二级24'),
    13 => array('id' => 13, 'pid' => 4, 'name' => '四级44'),
    14 => array('id' => 14, 'pid' => 1, 'name' => '二级26'),
    15 => array('id' => 15, 'pid' => 8, 'name' => '五级51'),
    16 => array('id' => 16, 'pid' => 8, 'name' => '五级52'),
    17 => array('id' => 17, 'pid' => 8, 'name' => '五级53'),
    18 => array('id' => 18, 'pid' => 16, 'name' => '六级64'),
);
echo "<pre>";
print_r(genTree($items));