轉載自http://blog.csdn.net/qishouzhang/article/details/47204359
<?php
/**
* Created by PhpStorm.
* User: qishou
* Date: 15-8-2
* Time: 上午12:00
*/
//準備數組,代替從數據庫中檢索出的數據(共有三個必須字段id,name,pid)
header("content-type:text/html;charset=utf-8");
$categories = array(
array('id'=>1,'name'=>'電腦','pid'=>0),
array('id'=>2,'name'=>'手機','pid'=>0),
array('id'=>3,'name'=>'筆記本','pid'=>1),
array('id'=>4,'name'=>'臺式機','pid'=>1),
array('id'=>5,'name'=>'智能機','pid'=>2),
array('id'=>6,'name'=>'功能機','pid'=>2),
array('id'=>7,'name'=>'超級本','pid'=>3),
array('id'=>8,'name'=>'遊戲本','pid'=>3),
);
/*======================非遞歸實現========================*/
$tree = array();
//第一步,將分類id作爲數組key,並創建children單元
foreach($categories as $category){
$tree[$category['id']] = $category;
$tree[$category['id']]['children'] = array();
}
//第二步,利用引用,將每個分類添加到父類children數組中,這樣一次遍歷即可形成樹形結構。
foreach($tree as $key=>$item){
if($item['pid'] != 0){
$tree[$item['pid']]['children'][] = &$tree[$key];//注意:此處必須傳引用傳遞,循環後面的數組的改變,同樣會影響此時的數組
if($tree[$key]['children'] == null){
unset($tree[$key]['children']); //如果children爲空,則刪除該children元素(可選)
}
}
}
////第三步,刪除無用的非根節點數據
foreach($tree as $key=>$category){
if($category['pid'] != 0){
unset($tree[$key]);
}
}
print_r($tree);
/*======================遞歸實現========================*/
$tree = $categories;
function get_attr($a,$pid){
$tree = array(); //每次都聲明一個新數組用來放子元素
foreach($a as $v){
if($v['pid'] == $pid){ //匹配子記錄
$v['children'] = get_attr($a,$v['id']); //遞歸獲取子記錄
if($v['children'] == null){
unset($v['children']); //如果子元素爲空則unset()進行刪除,說明已經到該分支的最後一個元素了(可選)
}
$tree[] = $v; //將記錄存入新數組
}
}
return $tree; //返回新數組
}
echo "<br/><br/><br/>";
print_r(get_attr($tree,0));