是的，是的，我知道，这里有很多关于数组排序的问题，但我需要一个更具体的解释
我有一个DB表来存储产品的多级菜单
比如：itemId，parentId，itemtitle
我用这个表在网页上构建菜单，使用reccurive函数，我想用这个DB表来获取后端html表单的数据，用于选项列表。DB中未排序的数据我需要正确排序并放入json数组中。我用这个做了一半的工作：
//empty arrays for sorting purposes
$ids = array();
$parents = array();
// iterate, $items - unsorted array from DB
foreach ($items as $key => $row) {
$ids[$key] = $row['itemId'];
$parents[$key] = $row['parentId'];
}
// sorting
array_multisort($ids, SORT_ASC, $parents, SORT_ASC, $items);
//now $items partly sorted
图1
因此$items列表如下所示：
(itemId-parentId-itemTitle(
1-0-***A
2-0-***B
3-0-***C
4-0-***D
6-1-***E
7-1-***F
8-1-***G
9-2-***H
10-2-***我
11-2-***J
12-2-***K
13-2-***L
14-3-***M
15-3-***N
16-3-***O
17-4-***P
18-4-***Q
图2
我需要：
1-0-***A
6-1-***E
7-1-***F
8-1-***G
2-0-***B
9-2-***H
10-2-***我
11-2-***J
12-2-***K
13-2-***L
3-0-***C
14-3-***M
15-3-***N
16-3-***O
4-0-***D
17-4-***P
18-4-***Q
所以问题是——如何以简洁的方式将数组从图1转换为图2的数组
所以这是我的荣幸。仅限两级菜单：
//get all categories, primary sorted by MySQL
$items = $cataloAR->query("SELECT itemId, parentId,itemTitle FROM `catalog` ORDER BY parentId, itemId");
//pre-sort by - itemId, parentId
$ids = array();//array for id`s
$parents = array();//array for parents
// get columns list
foreach ($items as $key => $row) {
$ids[$key] = $row['itemId'];
$parents[$key] = $row['parentId'];
}
// sort ascending by id, ascending by parent
array_multisort($ids, SORT_ASC, $parents, SORT_ASC, $items);
//make emptyarray for sorteddata, like - $entryList['itemId']['itemTitle']
$entryList = array();//empty array
$len = count($items); //count elements for proceeding
$currentEntry = 0; //current element number,start from 0-element
//iterate
//while reaching last element in list
while($currentEntry < $len){
//if current element is empty => go to next element
if (!isset($items[$currentEntry])) {
$currentEntry++;
}
//get current element from $items
//put it to $entryList
$entryList[] = $items[$currentEntry];
// get current id
$currentId = $items[$currentEntry]['itemId'];
//remove element from $items, because we just put it to the sorted list
unset($items[$currentEntry]);
//search in $items entries with patternId = $items['itemId']
//put to sorted list
//remove element
foreach ($items as $key => $value) {
if($value['parentId'] == $currentId){
$entryList[] = $value;
unset($items[$key]);
}
if (!isset($value)){
continue;
}
}
//increase counter
$currentEntry++;
}
//purge sorted list from empty elements $entryList
$sortedList = array_filter($entryList);
//Enjoy it!
return $sortedList;
我对您的数组做了一些假设，并用下面的代码创建了它。我能够通过创建两个新数组($root和$menu(来复制所需的输出，然后循环遍历每个数组来构建菜单。这很棘手，最好的答案实际上是从一开始就以不同的方式构建这个阵列，但如果这不可能，这段代码应该会让你到达你需要的地方：
$items[] = array('itemId' => 1,'parentId' => 0,'itemTitle' => '***A');
$items[] = array('itemId' => 2,'parentId' => 0,'itemTitle' => '***B');
$items[] = array('itemId' => 3,'parentId' => 0,'itemTitle' => '***C');
$items[] = array('itemId' => 4,'parentId' => 0,'itemTitle' => '***D');
$items[] = array('itemId' => 6,'parentId' => 1,'itemTitle' => '***E');
$items[] = array('itemId' => 7,'parentId' => 1,'itemTitle' => '***F');
$items[] = array('itemId' => 8,'parentId' => 1,'itemTitle' => '***G');
$items[] = array('itemId' => 9,'parentId' => 2,'itemTitle' => '***H');
$items[] = array('itemId' => 10,'parentId' => 2,'itemTitle' => '***I');
$items[] = array('itemId' => 11,'parentId' => 2,'itemTitle' => '***J');
$items[] = array('itemId' => 12,'parentId' => 2,'itemTitle' => '***K');
$items[] = array('itemId' => 13,'parentId' => 2,'itemTitle' => '***L');
$items[] = array('itemId' => 14,'parentId' => 3,'itemTitle' => '***M');
$items[] = array('itemId' => 15,'parentId' => 3,'itemTitle' => '***N');
$items[] = array('itemId' => 16,'parentId' => 3,'itemTitle' => '***O');
$items[] = array('itemId' => 17,'parentId' => 4,'itemTitle' => '***P');
$items[] = array('itemId' => 18,'parentId' => 4,'itemTitle' => '***Q');
foreach ($items as $itemArray) {
$parent = $itemArray['parentId'];
$item = $itemArray['itemId'];
$title = $itemArray['itemTitle'];
if ($parent == 0) {
// this is a root item
$root[$item] = $title;
} else {
// this is a submenu item
$menu[$parent][$item] = $title;
}
}
foreach ($root as $key => $value) {
// this is a root item, which is always 0.
echo "$key, 0, $value <br/>";
foreach ($menu as $parent => $item) {
if ($parent == $key) {
foreach ($item as $itemId => $title) {
// output the submenu items under the root
echo "$itemId, $parent, $title <br />";
}
}
}
}