從創建多維數組

Question

我在PHP中的數組嵌套列表，它看起來像這樣：

array (
    [0] => array (
     [id] => 1 
     [title] => "Title 1" 
     [parent_id] => NULL 
     [depth] => 0 
    ) 
    [1] => array (
     [id] => 2 
     [title] => "Title 2" 
     [parent_id] => NULL 
     [depth] => 0 
    ) 
    [2] => array (
     [id] => 3 
     [title] => "Title 3" 
     [parent_id] => 2 
     [depth] => 1 
    ) 
    [3] => array (
     [id] => 4 
     [title] => "Title 4" 
     [parent_id] => 2 
     [depth] => 1 
    ) 
    [4] => array (
     [id] => 5 
     [title] => "Title 5" 
     [parent_id] => NULL 
     [depth] => 0 
    ) 
    [5] => array (
     [id] => 6 
     [title] => "Title 6" 
     [parent_id] => 4 
     [depth] => 2 
    ) 
) 

我想要做的就是遍歷這個數組，並從它創建一個嵌套<ol>列表。所以結果應該是這樣的：

<ol> 
    <li>Title 1</li> // id = 1 
    <li>Title 2</li> // id = 2 
    <ol> 
     <li>Title 3</li> // id = 3 -> parent_id = 2 
     <li>Title 4</li> // id = 4 -> parent_id = 2 
     <ol> 
      <li>Title 6</li> // id = 6 -> parent_id = 4 
     </ol> 
    </ol> 
    <li>Title 5</li> // id = 5 
</ol> 

我一直在想辦法如何完成這件事。但到目前爲止，每一次嘗試失敗...

任何人任何想法如何，我可以創建這樣從這樣一個數組嵌套<ol>列表？

請注意，我沒有給定數據的控制。我只是做出一個API的調用，並返回JSON數據，我轉換成數組。和數組看起來就像我所描述的。

Answer 1

您應該使用遞歸：

首先在數組中的PHP'語法：

<?php 
$a=array (
    '0' => array (
     'id' => 1, 
     'title' => "Title 1", 
     'parent_id' => 'NULL', 
     'depth' => 0 
    ), 
    '1' => array (
     'id' => 2, 
     'title' => "Title 2", 
     'parent_id' => 'NULL', 
     'depth' => 0 
    ), 
    '2' => array (
     'id' => 3, 
     'title' => "Title 3", 
     'parent_id' => 2, 
     'depth' => 1 
    ), 
    '3' => array (
     'id' => 4, 
     'title' => "Title 4", 
     'parent_id' => 2, 
     'depth' => 1 
    ), 
    '4' => array (
     'id' => 5, 
     'title' => "Title 5", 
     'parent_id' => 'NULL', 
     'depth' => 0 
    ), 
    '5' => array (
     'id' => 6, 
     'title' => "Title 6", 
     'parent_id' => 4, 
     'depth' => 0 
    ) 
); 

這裏代碼：

$level = 'NULL'; 

function r($a, $level) { 
    $r = "<ol>"; 
    foreach ($a as $i) { 
     if ($i['parent_id'] == $level) { 
      $r = $r . "<li>" . $i['title'] . r($a, $i['id']) . "</li>"; 
     } 
    } 
    $r = $r . "</ol>"; 
    return $r; 
} 

print r($a, $level); 

?> 

的結果：

<ol><li>Title 1<ol></ol></li><li>Title 2<ol><li>Title 3<ol> 
</ol></li><li>Title 4<ol><li>Title 6<ol></ol></li></ol></li></ol></li><li>Title 5 
<ol></ol></li></ol> 

1. 標題1 \ n
2. 標題2 \ n
   1. 標題3 \ n
   2. 標題4 \ n
      1. 名稱6 \ n
3. 標題5 \ n

EDITED支票溶液後

爲了避免空葉子：

function r($a, $level) { 
    $r = '' ; 
    foreach ($a as $i) { 
     if ($i['parent_id'] == $level) { 
      $r = $r . "<li>" . $i['title'] . r($a, $i['id']) . "</li>"; 
     } 
    } 
    return ($r==''?'':"<ol>". $r . "</ol>"); 
} 

Answer 2

你可以嘗試以下

$array = array (
    "0" => array (
     "id" => 1, 
     "title" => "Title 1", 
     "parent_id" => NULL, 
     "depth" => 0 
    ), 
    "1" => array (
     "id" => 2, 
     "title" => "Title 2", 
     "parent_id" => NULL, 
     "depth" => 0 
    ), 
    "2" => array (
     "id" => 3, 
     "title" => "Title 3", 
     "parent_id" => 2, 
     "depth" => 1 
    ), 
    "3" => array (
     "id" => 4, 
     "title" => "Title 4", 
     "parent_id" => 2, 
     "depth" => 1 
    ), 
    "4" => array (
     "id" => 5, 
     "title" => "Title 5", 
     "parent_id" => NULL, 
     "depth" => 0 
    ), 
    "5" => array (
     "id" => 6, 
     "title" => "Title 6", 
     "parent_id" => 4, 
     "depth" => 0 
    ) 
); 

echo(make($array)); 

輸出

<ol> 
    <li>Title 1</li> 
    <li>Title 2</li> 
    <ol> 
     <li>Title 3</li> 
     <li>Title 4</li> 
     <ol> 
      <li>Title 6</li> 
     </ol> 
    </ol> 
    <li>Title 5</li> 
</ol> 

功能用於

function make(array $array, $no = 0) { 
    $child = hasChildren($array, $no); 
    if (empty($child)) 
     return ""; 
    $content = "<ol>\n"; 
    foreach ($child as $value) { 
     $content .= sprintf("\t<li>%s</li>\n", $value['title']); 
     $content .= make($array, $value['id']); 
    } 
    $content .= "</ol>\n"; 
    return $content; 
} 

function hasChildren($array, $id) { 
    return array_filter($array, function ($var) use($id) { 
     return $var['parent_id'] == $id; 
    }); 
} 

See Live Demo

Answer 3

以下數組：

Array 
(
    [0] => Content 
    [1] => Array 
     (
      [0] => International 
      [1] => Array 
       (
        [0] => Mexico 
        [1] => Array 
         (
          [0] => Tamaulipas 
         ) 

        [2] => USA 
       ) 

     ) 

) 

使用此功能：

function r($element) { 
    foreach ($element as $value) { 
     if (!is_array($value)) { 
      echo "<li>"; 
      echo $value; 
     } else { 
      echo "<ul>"; 
      r($value); 
      echo "</li>"; 
      echo "</ul>"; 
     } 
    } 
} 

PHP代碼：

echo "<ul>"; 
r($array); 
echo "</ul>"; 

退貨：

<ul> 
    <li>Public</li> 
    <li>User</li> 
    <li>Content 
     <ul> 
      <li>International 
       <ul> 
        <li>Mexico 
         <ul> 
          <li>Tamaulipas</li> 
         </ul> 
        </li> 
        <li>USA</li> 
       </ul> 
      </li> 
     </ul> 
    </li> 
</ul>