平面 PHP 数组到层次树 [英] Flat PHP Array to Hierarchy Tree
问题描述
我有一个包含以下键的数组
I have an array with the following keys
id
parent_id
name
一个示例数组:
array(7) {
[0]=>
array(3) {
["id"]=>
string(1) "4"
["parent_id"]=>
string(1) "0"
["name"]=>
string(16) "Top Level Page 4"
}
[1]=>
array(3) {
["id"]=>
string(1) "5"
["parent_id"]=>
string(1) "1"
["name"]=>
string(19) "Second Level Page 1"
}
[2]=>
array(3) {
["id"]=>
string(1) "6"
["parent_id"]=>
string(1) "2"
["name"]=>
string(19) "Second Level Page 2"
}
[3]=>
array(3) {
["id"]=>
string(1) "7"
["parent_id"]=>
string(1) "5"
["name"]=>
string(18) "Third Level Page 1"
}
[4]=>
array(3) {
["id"]=>
string(1) "3"
["parent_id"]=>
string(1) "0"
["name"]=>
string(16) "Top Level Page 3"
}
[5]=>
array(3) {
["id"]=>
string(1) "2"
["parent_id"]=>
string(1) "0"
["name"]=>
string(16) "Top Level Page 2"
}
[6]=>
array(3) {
["id"]=>
string(1) "1"
["parent_id"]=>
string(1) "0"
["name"]=>
string(16) "Top Level Page 1"
}
}
我想做的是使用这个数组显示一个层次树,我现在的代码正在生成:
What I would like to do is display a hierarchy tree using this array, the code I have at the moment is producing:
Top Level Page 4
--Second Level Page 1
---Second Level Page 2
----Third Level Page 1
Top Level Page 3
Top Level Page 2
Top Level Page 1
理想情况下,我需要生成以下结果,但级别不受限制:
Ideally I need to produce the below result but with unlimited levels:
Top Level Page 4
-Second Level Page 1
-Second Level Page 2
--Third Level Page 1
Top Level Page 3
Top Level Page 2
Top Level Page 1
我到目前为止的代码是:
The code I have so far is:
$level = 1;
foreach ($data as $row) {
if ($row['parent_id'] == 0) {
echo $row['name'] . '<br/>';
} else {
$level++;
foreach ($data as $m) {
if ($m['parent_id'] === $row['parent_id']) {
$c = 0;
$append = '';
while ($c < $level) {
$append.="-";
$c++;
}
echo $append . $row['name'] . '<br/>';
}
}
}
}
}
如果有人能给我一些关于如何实现这一点的指示,我将不胜感激.
If anyone could give me some pointers on how to achieve this it would be much appreciated.
我在这里找到了解决方案:从 PHP 数组为下拉选择字段创建嵌套列表
I found a solution here: Create nested list from PHP array for dropdown select field
推荐答案
你应该使用递归.
这是一个代码示例:
$datas = array(
array('id' => 1, 'parent' => 0, 'name' => 'Page 1'),
array('id' => 2, 'parent' => 1, 'name' => 'Page 1.1'),
array('id' => 3, 'parent' => 2, 'name' => 'Page 1.1.1'),
array('id' => 4, 'parent' => 3, 'name' => 'Page 1.1.1.1'),
array('id' => 5, 'parent' => 3, 'name' => 'Page 1.1.1.2'),
array('id' => 6, 'parent' => 1, 'name' => 'Page 1.2'),
array('id' => 7, 'parent' => 6, 'name' => 'Page 1.2.1'),
array('id' => 8, 'parent' => 0, 'name' => 'Page 2'),
array('id' => 9, 'parent' => 0, 'name' => 'Page 3'),
array('id' => 10, 'parent' => 9, 'name' => 'Page 3.1'),
array('id' => 11, 'parent' => 9, 'name' => 'Page 3.2'),
array('id' => 12, 'parent' => 11, 'name' => 'Page 3.2.1'),
);
function generatePageTree($datas, $parent = 0, $depth=0){
$ni=count($datas);
if($ni === 0 || $depth > 1000) return ''; // Make sure not to have an endless recursion
$tree = '<ul>';
for($i=0; $i < $ni; $i++){
if($datas[$i]['parent'] == $parent){
$tree .= '<li>';
$tree .= $datas[$i]['name'];
$tree .= generatePageTree($datas, $datas[$i]['id'], $depth+1);
$tree .= '</li>';
}
}
$tree .= '</ul>';
return $tree;
}
echo(generatePageTree($datas));
您可以在以下位置进行测试:http://phpfiddle.org/main/code/1qy-5fj
You can test it at: http://phpfiddle.org/main/code/1qy-5fj
或者如果您想要确切的格式:
Or if you want the exact format:
function generatePageTree($datas, $parent = 0, $depth = 0){
$ni=count($datas);
if($ni === 0 || $depth > 1000) return ''; // Make sure not to have an endless recursion
$tree = '';
for($i=0; $i < $ni; $i++){
if($datas[$i]['parent'] == $parent){
$tree .= str_repeat('-', $depth);
$tree .= $datas[$i]['name'] . '<br/>';
$tree .= generatePageTree($datas, $datas[$i]['id'], $depth+1);
}
}
return $tree;
}
测试:http://phpfiddle.org/main/code/jw3-s1j一个>
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