array_reduce使用動態變量傳遞在第二功能

Question

我具有低於$test陣列

 Array 
(
    [0] => Array 
     (
      [quantity] => 3 
      [stock_id] => _PHONE 
     ) 

    [1] => Array 
     (
      [quantity] => 3 
      [stock_id] => 102 
     ) 

    [2] => Array 
     (
      [quantity] => 4 
      [stock_id] => _PHONE 
     ) 

    [3] => Array 
     (
      [quantity] => 3 
      [stock_id] => 102 
     ) 

    [4] => Array 
     (
      [quantity] => 4 
      [stock_id] => _PHONE 
     ) 

    [5] => Array 
     (
      [quantity] => 6 
      [stock_id] => _PHONE 
     ) 

    [6] => Array 
     (
      [quantity] => 2 
      [stock_id] => 102 
     ) 

) 

和總結相同STOCK_ID鍵之一，我用下面的功能：

function sum($array, $key){ 
    isset($array[$key['stock_id']]) ? $array[$key['stock_id']]['quantity'] += $key['quantity'] : $array[$key['stock_id']] = $key; 
    return $array; 
}; 

//merge same stock_id and sum the quantity same stock id 
$sum_same_stock_id = array_reduce($test, "sum"); 

，結果順利如下圖所示：

$ sum_same_stock_id：

Array 
(
    [_PHONE] => Array 
     (
      [quantity] => 17 
      [stock_id] => _PHONE 
     ) 

    [102] => Array 
     (
      [quantity] => 8 
      [stock_id] => 102 
     ) 

) 

所以這裏的問題是，我想通過一個動態的鍵值不只是固定值stock_id & quantity在sum函數上面。嘗試了各種方法，但仍然無法想通。我們可以把這些功能放入課堂嗎？

任何意見是讚賞！

Answer 1

首先想到的是在數組中存儲所需值的另外兩個鍵。第三個參數包含初始值。類似這樣的：

function sum($array, $key){ 
     isset($array[$key['stock_id']]) ? $array[$key[$array['select']]][$array['sum']] += $key[$array['sum']] : $array[$key[$array['select']]] = $key; 
     return $array; 
    }; 

    //merge same stock_id and sum the quantity same stock id 

    $sum_same_stock_id = array_reduce($test, "sum", array('select'=>'stock_id', 'sum' => 'quantity'));