构造无限级分类数组

/**
 * 创建树形数组
 * @param array $array 分类数组
 * @param int $parentid 顶级分类id
 * @return array
 */
function createTree($array,$parentid=0){
    $result = array();
    foreach($array as $key => $val){
        if($val['parentid'] == $parentid) {
            $tmp = $array[$key];unset($array[$key]);
            count(createTree($array,$val['id'])) > 0 && $tmp['children'] = createTree($array,$val['id']);
            $result[$key] = $tmp;
        }
    }
    return $result;
}