試圖通過關聯數組循環時獲取未定義的索引

Question

我試圖通過關聯數組循環但獲取未定義的索引錯誤。以下是數組。

{ 
    "first":{ 
     "name":"name 1", 
     "products":[ 
      { 
       "id":2, 
       "product_id":123, 
       "category_id":1 
      }, 
      { 
       "id":3, 
       "product_id":"456" 
      } 
     ] 
    } 
} 

我通過這個像

foreach ($array as $category => $products) { 
    echo $category; 
    foreach ($products['products'] as $product) { 
     echo $product->id; 
    } 
} 

試圖循環，但我得到一個

Undefined index: products 

我如何遍歷數組的產品？

Answer 1

您需要更改$products['products']到$products->products因爲 $products是對象沒有陣列。

$test='{"first":{"name":"name 1","products":[ 
{"id":2,"product_id":123,"category_id":1},{"id":3,"product_id":"456"} 
]}}'; 
echo "<pre>"; 
$array=json_decode($test); 
foreach($array as $category => $products){ 
    foreach($products->products as $product){ 
     echo $product->id."<br/>"; 
    }     
} 

demo.....