php - 递归函数php

Question

我有一个看起来像这样的数组

$dataArray = array (
  0 => 
  array (
    'UserId' => '804023',
    'ProjectCode' => 'RA1234',
    'Role' => 'PI',
  ),
  1 => 
  array (
    'UserId' => '804023',
    'ProjectCode' => 'RA1234',
    'Role' => 'PM',
  ),
  2 => 
  array (
    'UserId' => '804023',
    'ProjectCode' => 'A90123',
    'Role' => 'CI',
  ),
  3 => 
  array (
    'UserId' => '804023',
    'ProjectCode' => 'A20022',
    'Role' => 'PM',
  ),
)

我需要它看起来像这样

$expected = array (
  804023 => 
  array (
    'RA1234' => 
    array (
      0 => 'PI',
      1 => 'PM',
    ),
    'A90123' => 
    array (
      0 => 'PI',
    ),
    'A20022' => 
    array (
      0 => 'CI',
    ),
  ),
)

我认为这可以使用递归来实现，因为这是我可能多次遇到的场景

我已经在形成嵌套数组键的键数组中传递了这么远，即

$keys=array("UserId","projectCode","Role");

但只是没有看到从这里去哪里有任何指示？

public function structureData(array $data, array $keys)
 {
  //$structuredData = array();


  foreach ($data as $key => $value)
  {
   $keyForData = array_slice($keys,0,1);


   $remainingKeys = $keys;
   array_shift($remainingKeys);

   if (!array_key_exists($value[$keyForData[0]], $structuredData))
   {

    $count=count($remainingKeys);


    $structuredData[$value[$keyForData[0]]] =array();
    // this returns as expected array(804023 =>array ()); but subsequent recursive calls with the remaining data fail



   }

  }
  return $structuredData);
}

Answer 1

一个粗糙但有效的解决方案。

function structureData($data, $keys){                                           
    $out = array();                                                             
    foreach($data as $row){                                                     
        $subout = &$out;                                                        
        foreach(array_slice($keys, 0, -1) as $key){                             
            $value = $row[$key];                                                
            $subout = &$subout[$value];                                         
        }                                                                       
        $subout[] = $row[$keys[count($keys) - 1]];                              

    }                                                                           
    return $out;                                                                
}                                                                               

print_r(structureData($dataArray, array('UserId', 'ProjectCode', 'Role')));