[英]PHP Building Recursive Array from List
我從 MySQL 數據庫返回頁面列表及其父頁面,並將所有結果放入一個數組中,如下所示,其中每個結果都是一個數組,其中包括論壇的父、名稱和 id(數組頁面的鍵也是與頁面 ID 相同)。
為了model和應用,還有一些其他參數。
因此,MySQL 查詢將返回此數據集。
pages=>
[1] => array(id=>1,
parent=>0,
name=>Hello World)
[2] => array(id=>1,
parent=>1,
name=>Child of Hello World)
[3] => array(id=>1,
parent=>0,
name=>Brother of Hello World)
[4] => array(id=>4,
parent=>2,
name=Grand-child of Hello World)
[6] => array(id=>6,
parent=>4,
name=Great-grand-child of Hello World)
然后我想將數組轉換成看起來像這樣的東西
pages=>
[1] => id=>1,
name=>Hello World
children=>
[2] => id=>1
name=>Child of Hello World
children=>
[4] =>
id=>4
name=> Grand-child of Hello World)
children=>
[6] =>
id=>6
name=> Great-grand-child of Hello World
children= null
[3] => array(id=>1,
name=>Brother of Hello World
children=>null
所以基本上,我想把一個線性數組變成一個嵌套的多維數組,這樣我就可以打印我的站點地圖了。
它需要是一個遞歸解決方案。 有超過 700 頁和多達 5 或 6 個級別。
我只想做 1 個 mysql 查詢。 不是 700 所以請不要給我一個基於 mysql 的解決方案。
<?php
$pages = array();
$pages[1] = array('id' => 1, 'parent' => 0, 'name' => 'Hello World');
$pages[2] = array('id' => 1, 'parent' => 1, 'name' => 'Child of Hello World');
$pages[3] = array('id' => 1, 'parent' => 0, 'name' => 'Brother of Hello World');
$pages[4] = array('id' => 4, 'parent' => 2, 'name' => 'Grand-child of Hello World');
$pages[6] = array('id' => 6, 'parent' => 4, 'name' => 'Great-grand-child of Hello World');
$children = array();
foreach($pages as $key => $page){
$parent = (int)$page['parent'];
if(!isset($children[$parent]))
$children[$parent] = array();
$children[$parent][$key] = array('id' => $page['id'], 'name' => $page['name']);
}
$new_pages = recursive_append_children($children[0], $children);
function recursive_append_children($arr, $children){
foreach($arr as $key => $page)
if(isset($children[$key]))
$arr[$key]['children'] = recursive_append_children($children[$key], $children);
return $arr;
}
print_r($new_pages);
?>
輸出:
Array
(
[1] => Array
(
[id] => 1
[name] => Hello World
[children] => Array
(
[2] => Array
(
[id] => 1
[name] => Child of Hello World
[children] => Array
(
[4] => Array
(
[id] => 4
[name] => Grand-child of Hello World
[children] => Array
(
[6] => Array
(
[id] => 6
[name] => Great-grand-child of Hello World
)
)
)
)
)
)
)
[3] => Array
(
[id] => 1
[name] => Brother of Hello World
)
)
這是一個構建樹的快速遞歸 function。 請注意,它不是很好(一個原因是因為它不會刪除已經添加到樹中的項目,所以每次你遞歸它都會遍歷整個列表) - 但它應該足以讓你開始。
function buildTree($itemList, $parentId) {
// return an array of items with parent = $parentId
$result = array();
foreach ($itemList as $item) {
if ($item['parent'] == $parentId) {
$newItem = $item;
$newItem['children'] = buildTree($itemList, $newItem['id']);
$result[] = $newItem;
}
}
if (count($result) > 0) return $result;
return null;
}
$myTree = buildTree($myArray, 0);
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