无法访问对象属性php

Question

我在奖励-object.php文件中有以下对象：

<?php

$rewards_obj_data = array(
    array(
    'reward_id' => 0,
    'reward_mile_text' => "mile 0",
    'reward_title' => "Tag Connected Watch",
    'reward_img' => "../assets/rewards/rewards-1.jpg",
    'reward_apr' => "Representative 18.9% APR (variable)",
    'reward_cta_url' => "rewards/claimReward.jsp&rewardID=0"/* + auth cookie details */,
    ),
    array(
    'reward_id' => 1,
    'reward_mile_text' => "mile 1",
    'reward_title' => "Tag Connected Watch",
    'reward_img' => "../assets/rewards/rewards-1.jpg",
    'reward_apr' => "Representative 18.9% APR (variable)",
    ),    
    array(
    'reward_id' => 2,
    'reward_mile_text' => "mile 2",
    'reward_title' => "Tag Connected Watch",
    'reward_img' => "../assets/rewards/rewards-1.jpg",
    'reward_apr' => "Representative 18.9% APR (variable)",
    ),    
    array(
    'reward_id' => 3,
    'reward_mile_text' => "mile 3",
    'reward_title' => "Tag Connected Watch",
    'reward_img' => "../assets/rewards/rewards-1.jpg",
    'reward_apr' => "Representative 18.9% APR (variable)",
    ),    
    array(
    'reward_id' => 4,
    'reward_mile_text' => "mile 4",
    'reward_title' => "Tag Connected Watch",
    'reward_img' => "../assets/rewards/rewards-1.jpg",
    'reward_apr' => "Representative 18.9% APR (variable)",
    ),    
);

?>

我试图在另一个for循环中访问它的属性：

<?php
    require '../api/rewards-object.php';

   // in between here I make some API calls to retrive an array of objects which I have named $rewardsAPIResponse

    // parse http request
    $decode_rewardsAPIResponse = json_decode($rewardsAPIResponse);

    /* for loop */
    foreach($decode_rewardsAPIResponse as $key=>$value){

        $IdFromApi = $value->rewardID;

         $test = json_encode($rewards_obj_data[$IdFromApi]->reward_title);
        echo $test;
    };
?>

这里的想法是使用从API返回的对象的id来获取奖励-object.php文件中的对象。

现在，如果我替换这一行：

     $test = json_encode($rewards_obj_data[$IdFromApi]->reward_id);
    echo $test;

通过以下方式：

     $test = json_encode($rewards_obj_data[$IdFromApi]);
    echo $test;

然后，它获取的对象，没有问题！问题在于我试图访问对象属性(如reward_title )。这里，它返回一个null值。我一直在玩json_encode的角色，因为我认为这可能是问题所在，但到目前为止，我所尝试的一切都没有起作用。知道我哪里出了问题吗？

Answer 1

$rewards_obj_data是一个数组，内容也是一个数组。但是你试着像一个对象一样去访问它。它是一个数组，不是一个对象。这将是正确的方法：

$rewards_obj_data[$IdFromApi]['reward_id']

Answer 2

我没有看到物体，而是二维数组。以$rewards_obj_data[$IdFromApi]['reward_title'];的形式访问您的值

Answer 3

数组不是对象。在PHP中，数组可能存在整数键和字符串键，也许这就是混淆。

echo $rewards_obj_data[0]['reward_id']; // 0

foreach($rewards_obj_data as $value){
  echo $value['reward_id'];
}

// Convert array to to string, converting arrays to objects.
$json = json_encode($rewards_obj_data, JSON_FORCE_OBJECT);

// Convert json to a PHP object.
$data = json_decode($json);

foreach($data as $obj){
  echo $obj->reward_id;
}