通過php對象數組的鍵值獲得值

Question

我有一個PHP對象，我試圖通過鍵獲取值而不使用foreach。

如果我做下面我能夠得到的值：

$item_data_decode->meta_data[0]->value; 

但項目可能在不同的順序，以便能夠在這種方法不計，我需要使用密鑰然而，這並不工作：

$item_data_decode->meta_data['First Name']; 

代碼：

$item_data_decode = json_decode($item_values); 
if (!empty($item_data_decode->meta_data)) { 
    $fName = $item_data_decode->meta_data['First Name']->value; 
} 

對象：

$a = new stdClass(); 
$a->meta_data = array(); 
$a->meta_data[0] = new stdClass(); 
$a->meta_data[0]->id = "2113"; 
$a->meta_data[0]->key = "First Name"; 
$a->meta_data[0]->value = "Recipient First Name"; 
$a->meta_data[1] = new stdClass(); 
$a->meta_data[1]->id = "2114"; 
$a->meta_data[1]->key = "Last Name"; 
$a->meta_data[1]->value = "Recipient Last Name"; 
$a->meta_data[2] = new stdClass(); 
$a->meta_data[2]->id = "2115"; 
$a->meta_data[2]->key = "addressLine 1"; 
$a->meta_data[2]->value = "Recipient Address Line 1"; 
$a->meta_data[3] = new stdClass(); 
$a->meta_data[3]->id = "2116"; 
$a->meta_data[3]->key = "addressLine2"; 
$a->meta_data[3]->value = "Recipient Address Line 2"; 
$a->meta_data[4] = new stdClass(); 
$a->meta_data[4]->id = "2117"; 
$a->meta_data[4]->key = "City"; 
$a->meta_data[4]->value = "Recipient Town/City"; 
$a->meta_data[5] = new stdClass(); 
$a->meta_data[5]->id = "2118"; 
$a->meta_data[5]->key = "Region"; 
$a->meta_data[5]->value = "Recipient Region/County"; 
$a->meta_data[6] = new stdClass(); 
$a->meta_data[6]->id = "2119"; 
$a->meta_data[6]->key = "Country"; 
$a->meta_data[6]->value = "N/A"; 
$a->meta_data[7] = new stdClass(); 
$a->meta_data[7]->id = "2120"; 
$a->meta_data[7]->key = "Postcode"; 
$a->meta_data[7]->value = "Recipient Postcode"; 


// outputs 
[meta_data] => Array ([0] => stdClass Object ([id] => 2113 [key] => First Name [value] => Recipient First Name) [1] => stdClass Object ([id] => 2114 [key] => Last Name [value] => Recipient Last Name) [2] => stdClass Object ([id] => 2115 [key] => addressLine 1 [value] => Recipient Address Line 1) [3] => stdClass Object ([id] => 2116 [key] => addressLine2 [value] => Recipient Address Line 2) [4] => stdClass Object ([id] => 2117 [key] => City [value] => Recipient Town/City) [5] => stdClass Object ([id] => 2118 [key] => Region [value] => Recipient Region/County) [6] => stdClass Object ([id] => 2119 [key] => Country [value] => N/A) [7] => stdClass Object ([id] => 2120 [key] => Postcode [value] => Recipient Postcode)) 

添加true到json_decode提供以下內容：

Array ([id] => 232 [order_id] => 320 [name] => Tb [product_id] => 50 [variation_id] => 0 [quantity] => 1 [tax_class] => [subtotal] => 50 [subtotal_tax] => 0 [total] => 50 [total_tax] => 0 [taxes] => Array ([total] => Array () [subtotal] => Array ()) [meta_data] => Array ()) Array ([id] => 233 [order_id] => 320 [name] => Turtle Bay Gift Card [product_id] => 50 [variation_id] => 0 [quantity] => 1 [tax_class] => [subtotal] => 30 [subtotal_tax] => 0 [total] => 30 [total_tax] => 0 [taxes] => Array ([total] => Array () [subtotal] => Array ()) [meta_data] => Array ([0] => Array ([id] => 2113 [key] => First Name [value] => Recipient First Name) [1] => Array ([id] => 2114 [key] => Last Name [value] => Recipient Last Name) [2] => Array ([id] => 2115 [key] => addressLine 1 [value] => Recipient Address Line 1) [3] => Array ([id] => 2116 [key] => addressLine2 [value] => Recipient Address Line 2) [4] => Array ([id] => 2117 [key] => City [value] => Recipient Town/City) [5] => Array ([id] => 2118 [key] => Region [value] => Recipient Region/County) [6] => Array ([id] => 2119 [key] => Country [value] => N/A) [7] => Array ([id] => 2120 [key] => Postcode [value] => Recipient Postcode))) 

Answer 1

我個人準備這樣的數據：

$item_data_decode = json_decode($item_values, true); 
$meta_array = array_combine(array_column($item_data_decode['meta_data'], 'key'), $item_data_decode['meta_data']); 

if (!empty($meta_array['First Name'])) { 
    $fName = $meta_array['First Name']['value']; 
} 

在json_decode第二PARAM確保它只返回陣列（ Manual.）。這樣你就可以使用像array_column（Manual）和array_combine（Manual）這樣的數組函數，並且得到一個非常接近你想要的結構的數組。

Test Case，因爲沒有代碼是簡寫它。

Answer 2

如果你可以修改陣列結構，然後構建這樣說：

array(
    'First Name'=>array(
     'id'=>2113, 
     'value'=>'Recipient First Name' 
    ), 
    'Last Name'=>array(
     'id'=>2114, 
     'value'=>'Recipient Last Name' 
    ), 
    . . . 
); 

然後，您可以仍然使用這個數組在foreach循環中，如果需要的話，儘管有一些變化，但能夠直接訪問你想要的值。

如果您無法修改陣列結構，那麼您運氣不佳，並且如果要查找所需的值，則需要循環foreach。

如果您擔心的是多次訪問數組的性能，那麼請考慮在處理之前將數組轉換爲上面的結構。

編輯

例陣列變換：

$transformed_array = array(); 
foreach($item_data_decode->meta_data as $data) { 
    $transformed_array[$data['key']] = array(
     'id'=>$data['id'], 
     'value'=>$data['value'] 
    ); 
} 

Answer 3

爲了保持一切不同，我在PHP腳本中包含了JSON。

訪問每個屬性是如何通常訪問對象的屬性。
請注意，由於"First name"有一個空格，因此無法用箭頭符號訪問它，並且必須用大括號括起來。對於沒有空間的任何房產，不需要花括號。

您的代碼失敗的原因是因爲您嘗試使用用於數組的方括號表示法訪問屬性。

我知道你不能編輯實際的數組輸出，但是如果你可以編輯JSON，那麼這將解決你的問題。

$item_data_decode = json_decode('{ 
    "meta_data": { 
     "First name": { 
      "id": 2113, 
      "key": "First name", 
      "value": "Recipient First Name" 
     }, 
     "Last Name": { 
      "id": 2114, 
      "key": "Last Name", 
      "value": "Recipient Last Name" 
     }, 
     "addressLine 1": { 
      "id": 2115, 
      "key": "addressLine 1", 
      "value": "Recipient Address Line 1" 
     }, 
     "addressLine2": { 
      "id": 2116, 
      "key": "addressLine2", 
      "value": "Recipient Address Line 2" 
     }, 
     "City": { 
      "id": 2117, 
      "key": "City", 
      "value": "Recipient Town/City" 
     }, 
     "Region": { 
      "id": 2118, 
      "key": "Region", 
      "value": "Recipient Region/County" 
     }, 
     "Country": { 
      "id": 2119, 
      "key": "Country", 
      "value": "N/A" 
     }, 
     "Postcode": { 
      "id": 2120, 
      "key": "Postcode", 
      "value": "Recipient Postcode" 
     } 
    } 
}'); 

var_dump($item_data_decode->meta_data->{"First name"}->value); // outputs "Recipient First Name"