陣列與關聯數組

Question

減少我有這樣

$filter_array = Array 
    (
     [0] => Array 
      (
       [fv_id] => 1 
       [fv_value] => Red 
       [filter_id] => 1 
       [filter_name] => Color 
      ) 

     [1] => Array 
      (
       [fv_id] => 2 
       [fv_value] => Blue 
       [filter_id] => 1 
       [filter_name] => Color 
      ) 

    ) 

我想通過具有上陣列的頂部FILTER_NAME和過濾器_id這對於所有陣列類似，以減少陣列的陣列。

$newArray = array_reduce($filter_array,function($carry,$item){ 

      $allFilterValues[] = array(
       'fv_id' => $item['fv_id'], 
       'fv_value' => $item['fv_value'], 
      ); 

      $formated_array = array(
       'filter_id' => $item['filter_id'], 
       'filter_name' => $item['filter_name'], 
       'filter_values' => $allFilterValues 
      ); 
      return $formated_array; 
     }); 

但我剛開最後一個數組迭代值上filter_values

Array 
(
    [filter_id] => 1 
    [filter_name] => Color 
    [filter_values] => Array 
     (
      [0] => Array 
       (
        [fv_id] => 2 
        [fv_value] => Blue 
       ) 

     ) 

) 

但我想數組是這樣的。

Array 
(
    [filter_id] => 1 
    [filter_name] => Color 
    [filter_values] => Array 
     (
       [0] => Array 
       (
        [fv_id] => 1 
        [fv_value] => Red 
       ), 

       [1] => Array 
       (
        [fv_id] => 2 
        [fv_value] => Blue 
       ) 

     ) 

) 

Answer 1

在array_reduce回調函數的每次迭代必須返回當前$carry值：

$newArray = array_reduce($filter_array,function($carry,$item){ 
    // create key so as to distinct values from each other 
    $key = $item['filter_id'] . '-' . $item['filter_name']; 

    // check if created key exists in `$carry`, 
    // if not - we init it with some data 
    if (empty($carry[$key])) { 
     $carry[$key] = [ 
      'filter_id' => $item['filter_id'], 
      'filter_name' => $item['filter_name'], 
      'filter_values' => [] 
     ]; 
    } 

    // add values to `filter_values` 
    $carry[$key]['filter_values'][] = [ 
     'fv_id' => $item['fv_id'], 
     'fv_value' => $item['fv_value'], 
    ]; 

    return $carry; 
}, []); 

// if you want to reindex `$newArray` from 0: 
$newArray = array_values($newArray); 

更新：當且僅當在'filter_id'和'filter_name'你$filter_array值總是的同樣你可以簡化你的代碼：

$newArray = []; 
$first = true; 
foreach ($filter_array as $item) { 
    if ($first) { 
     $first = false; 
     $newArray = [ 
      'filter_id' => $item['filter_id'], 
      'filter_value' => $item['filter_name'], 
      'filter_values' => [] 
     ]; 
    } 

    $newArray['filter_values'][] = [ 
     'fv_id' => $item['fv_id'], 
     'fv_value' => $item['fv_value'], 
    ]; 
} 
echo'<pre>',print_r($newArray),'</pre>';