| 2 | /** |
| 3 | * Created by PhpStorm. |
| 4 | * User: qishou |
| 5 | * Date: 15-8-2 |
| 6 | * Time: 上午12:00 |
| 7 | */ |
| 8 | //准备数组，代替从数据库中检索出的数据(共有三个必须字段id,name,pid) |
| 9 | header("content-type:text/html;charset=utf-8"); |
| 10 | $categories = array( |
| 11 | array('id'=>1,'name'=>'电脑','pid'=>0), |
| 12 | array('id'=>2,'name'=>'手机','pid'=>0), |
| 13 | array('id'=>3,'name'=>'笔记本','pid'=>1), |
| 14 | array('id'=>4,'name'=>'台式机','pid'=>1), |
| 15 | array('id'=>5,'name'=>'智能机','pid'=>2), |
| 16 | array('id'=>6,'name'=>'功能机','pid'=>2), |
| 17 | array('id'=>7,'name'=>'超级本','pid'=>3), |
| 18 | array('id'=>8,'name'=>'游戏本','pid'=>3), |
| 19 | ); |
| 20 | |
| 21 | /*======================非递归实现========================*/ |
| 22 | $tree = array(); |
| 23 | //第一步，将分类id作为数组key,并创建children单元 |
| 24 | foreach($categories as $category){ |
| 25 | $tree[$category['id']] = $category; |
| 26 | $tree[$category['id']]['children'] = array(); |
| 27 | } |
| 28 | //第二步，利用引用，将每个分类添加到父类children数组中，这样一次遍历即可形成树形结构。 |
| 29 | foreach($tree as $key=>$item){ |
| 30 | if($item['pid'] != 0){ |
| 31 | $tree[$item['pid']]['children'][] = &$tree[$key];//注意：此处必须传引用否则结果不对 |
| 32 | if($tree[$key]['children'] == null){ |
| 33 | unset($tree[$key]['children']); //如果children为空，则删除该children元素（可选） |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | ////第三步，删除无用的非根节点数据 |
| 38 | foreach($tree as $key=>$category){ |
| 39 | if($category['pid'] != 0){ |
| 40 | unset($tree[$key]); |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | print_r($tree); |
| 45 | |
| 46 | /*======================递归实现========================*/ |
| 47 | $tree = $categories; |
| 48 | function get_attr($a,$pid){ |
| 49 | $tree = array(); //每次都声明一个新数组用来放子元素 |
| 50 | foreach($a as $v){ |
| 51 | if($v['pid'] == $pid){ //匹配子记录 |
| 52 | $v['children'] = get_attr($a,$v['id']); //递归获取子记录 |
| 53 | if($v['children'] == null){ |
| 54 | unset($v['children']); //如果子元素为空则unset()进行删除，说明已经到该分支的最后一个元素了（可选） |
| 55 | } |
| 56 | $tree[] = $v; //将记录存入新数组 |
| 57 | } |
| 58 | } |
| 59 | return $tree; //返回新数组 |
| 60 | } |
| 61 | echo " "; |
| 62 | |
| 63 | print_r(get_attr($tree,0)); |
