php - 嵌套数组的 PHP 邻接数据

Question

我有如下数组：

Array
(
    [0] => Array
        (
            [question_id] => 1
            [question_title] => Q1
            [child_question_id] => NULL 
        )

    [1] => Array
        (
            [question_id] => 2
            [question_title] => Q2
            [child_question_id] => NULL
        )

    [2] => Array
        (
            [question_id] => 3
            [question_title] => Q3
            [child_question_id] => 4
        )

    [3] => Array
        (
            [question_id] => 3
            [question_title] => Q3
            [child_question_id] => 5
        )

    [4] => Array
        (
            [question_id] => 4
            [question_title] => Q4
            [child_question_id] => NULL
        )

    [5] => Array
        (
            [question_id] => 5
            [question_title] => Q5
            [child_question_id] => NULL
        )

    [6] => Array
        (
            [question_id] => 6
            [question_title] => Q6
            [child_question_id] => NULL
        )

    [7] => Array
        (
            [question_id] => 7
            [question_title] => Q7
            [child_question_id] => 6
        )

)

并使用 PHP 我期望结果为：

Array
(
    [0] => Array
        (
            [question_id] => 1
            [question_title] => Q1
            [child_question_id] => NULL 
        )

    [1] => Array
        (
            [question_id] => 2
            [question_title] => Q2
            [child_question_id] => NULL
        )

    [2] => Array
        (
            [question_id] => 3
            [question_title] => Q3
            [children] => array(
               [0] => Array
               (
                  [question_id] => 4
                  [question_title] => Q4
               )

              [1] => Array
              (
                  [question_id] => 5
                  [question_title] => Q5
               )

              )
        )

    [3] => Array
        (
            [question_id] => 7
            [question_title] => Q7
            [children] => array(
              [0] => Array
               (
                    [question_id] => 6
                    [question_title] => Q6
               )
              )
        )

)

我尝试使用以下逻辑构建最终数组：

1. 遍历数组以收集子 ID 和子数据
2. 再次遍历数组并将项目子 id 与之前形成的子数组匹配，如果找到则创建子数组

你能帮我创造更好的解决方案吗？

Answer 1

你的意思是这样的吗？

$i = 0;
$new = array();
$unsetter = array();
foreach($array as $val)
{
    $new[$i] = array();
    foreach($val as $key => $data)
    {
        if(($key == 'child_question_id') && (!is_null($data)))
        {
            $new[$i]['children'] = array();
            $new[$i]['children']['question_id'] = $data;
            $new[$i]['children']['question_title'] = $array[$data]['question_title'];
            $unsetter[] = $data; 


        } else {
            $new[$i][$key] = $data;
        }
    }
    $i++;
}
foreach($unsetter as $uns)
{
        unset($new[$uns]);
}
$new = array_values($new);
var_dump($new);

这将输出

array (size=5)
  0 => 
    array (size=3)
      'question_id' => int 1
      'question_title' => string 'Q1' (length=2)
      'child_question_id' => null
  1 => 
    array (size=3)
      'question_id' => int 2
      'question_title' => string 'Q2' (length=2)
      'child_question_id' => null
  2 => 
    array (size=3)
      'question_id' => int 3
      'question_title' => string 'Q3' (length=2)
      'children' => 
        array (size=2)
          'question_id' => int 4
          'question_title' => string 'Q4' (length=2)
  3 => 
    array (size=3)
      'question_id' => int 3
      'question_title' => string 'Q3' (length=2)
      'children' => 
        array (size=2)
          'question_id' => int 5
          'question_title' => string 'Q5' (length=2)
  4 => 
    array (size=3)
      'question_id' => int 7
      'question_title' => string 'Q7' (length=2)
      'children' => 
        array (size=2)
          'question_id' => int 6
          'question_title' => string 'Q6' (length=2)

现场演示