如何在 PHP 中解码 JSON 字符串？答案

【问题标题】：How to decode a JSON string in PHP?如何在 PHP 中解码 JSON 字符串？
【发布时间】：2009-08-12 21:21:45
【问题描述】：

我有一个如下所示的 JSON 字符串：

{"addresses":{"address":[{"@array":"true","@id":"888888","@uri":"xyz","household":{"@id":"44444","@uri":"xyz"},"person":{"@id":"","@uri":""},"addressType":{"@id":"1","@uri":"xyz","name":"Primary"},"address1":"xyz","address2":null,"address3":null,"city":"xyz","postalCode":"111111"}]}}

什么是 PHP 来解码这个并将 address1、address2、address3、city 和 postalCode 放入会话变量中？

到目前为止，我尝试了这个，但它不起作用：

$results = json_decode(strstr($address, '{"addresses":{"address":[{'), true);
$_SESSION['address1'] = $results['address']['address1'];

谢谢！

【问题讨论】：

您希望发生的事情没有发生？总是描述你想要的行为和你得到的行为。
在输出任何内容和引用 $_SESSION 之前，您是否致电 session_start()？
这么多的答案...这么少的问题upvotes。
许多答案通常意味着简单的问题，而不是好的问题。
对某些人来说很容易，但对其他人来说很容易，因此是这个问题。

标签： php json

【解决方案1】：

print_r 是你搞清楚 JSON 结构的朋友。

<?php

$addresses = json_decode('{"addresses":{"address":[{"@array":"true","@id":"888888","@uri":"xyz","household":{"@id":"44444","@uri":"xyz"},"person":{"@id":"","@uri":""},"addressType":{"@id":"1","@uri":"xyz","name":"Primary"},"address1":"xyz","address2":null,"address3":null,"city":"xyz","postalCode":"111111"}]}}');

$_SESSION['address1'] = $addresses->addresses->address[0]->address1;
$_SESSION['address2'] = $addresses->addresses->address[0]->address2;
$_SESSION['address3'] = $addresses->addresses->address[0]->address3;
$_SESSION['city'] = $addresses->addresses->address[0]->city;
$_SESSION['postalCode'] = $addresses->addresses->address[0]->postalCode;

print_r($_SESSION);

结果：

Array
(
    [address1] => xyz
    [address2] => 
    [address3] => 
    [city] => xyz
    [postalCode] => 111111
)

【讨论】：

+1 要像显示的那样漂亮地打印结果，请在 print_r() 之后添加
```
 标记。这让我永远想通了！
```
太棒了！！！！非常感谢，这个就搞定了。我没有提到我正在使用 strstr，因为我在 $addresses 中包含一些其他标头信息并且需要将其删除。但这完成了工作，我非常感激！！！

【解决方案2】：

json_decode 会将 json 格式的字符串解码为 PHP object。

试试这个：

$results = json_decode($address);
$results['address1'] = $results->addresses->address[0]->address1;
$results['address2'] = $results->addresses->address[0]->address2;
$results['address3'] = $results->addresses->address[0]->address3;
$results['city'] = $results->addresses->address[0]->city;
$results['postalCode'] = $results->addresses->address[0]->postalCode;

编辑 - 更新，我一开始误读了你的 JSON。

【讨论】：

【解决方案3】：

请注意，这些“@array”和“@id”字段是无效的 JSON 表示法，从技术上讲，它们会导致 JSON 解析器出现未指定的行为。

【讨论】：

【解决方案4】：

为什么不解码整个 JSON 字符串然后得到你需要的？

$address = '{"addresses":{"address":[{"@array":"true","@id":"888888","@uri":"xyz","household":{"@id":"44444","@uri":"xyz"},"person":{"@id":"","@uri":""},"addressType":{"@id":"1","@uri":"xyz","name":"Primary"},"address1":"xyz","address2":null,"address3":null,"city":"xyz","postalCode":"111111"}]}}';
$results = json_decode($address, true);
$address = $results['addresses']['address'][0];
print $address['address1'];
print $address['address2'];
print $address['postalCode'];

【讨论】：

【解决方案5】：

也许可以试试 $results['addresses']['address']['address1'];

不知道为什么要使用 strstr。但在这种情况下，它看起来不会改变任何东西。

【讨论】：

【解决方案6】：

您可以使用 print_r 输出 $results 以准确找出对象输出的样子。

【讨论】：

【解决方案7】：

如果你对你的数组进行 print_r，你会看到布局是怎样的：

stdClass Object
(
  [addresses] => stdClass Object
    (
      [address] => Array
        (
          [0] => stdClass Object
            (
              [@array] => true
              [@id] => 888888
              [@uri] => xyz
              [household] => stdClass Object
                (
                  [@id] => 44444
                  [@uri] => xyz
                )

              [person] => stdClass Object
                (
                  [@id] => 
                  [@uri] => 
                )

              [addressType] => stdClass Object
                (
                  [@id] => 1
                  [@uri] => xyz
                  [name] => Primary
                )

              [address1] => xyz
              [address2] => 
              [address3] => 
              [city] => xyz
              [postalCode] => 111111
            )
        )
    )
)

【讨论】：

【解决方案8】：

json_decode($jsonData) 顺便返回一个对象，而不是数组。

例如：

stdClass Object
(
    [addresses] => stdClass Object
        (
            [address] => Array
                (
                    [0] => stdClass Object
                        (
                            [@array] => true
                            [@id] => 888888
                            [@uri] => xyz
                            [household] => stdClass Object
                                (
                                    [@id] => 44444
                                    [@uri] => xyz
                                )

                            [person] => stdClass Object
                                (
                                    [@id] => 
                                    [@uri] => 
                                )

                            [addressType] => stdClass Object
                                (
                                    [@id] => 1
                                    [@uri] => xyz
                                    [name] => Primary
                                )

                            [address1] => xyz
                            [address2] => 
                            [address3] => 
                            [city] => xyz
                            [postalCode] => 111111
                        )

                )

        )

)

访问数据的方式：

$object = json_decode($jsonString);
$object->addresses->address[0]; // First address object
$object->addresses->address[0]->{"@array"}; // Not good way to access object property (damn @)
$object->addresses->address[0]->address1;
$object->addresses->address[0]->addressType->{"@id"}; // Again damn @

【讨论】：

【解决方案9】：

这会将所有标量和空值放入会话中，其中键不以@开头

$jsonString = '{"addresses":{"address":[{"@array":"true","@id":"888888","@uri":"xyz","household":{"@id":"44444","@uri":"xyz"},"person":{"@id":"","@uri":""},"addressType":{"@id":"1","@uri":"xyz","name":"Primary"},"address1":"xyz","address2":null,"address3":null,"city":"xyz","postalCode":"111111"}]}}';

$result = json_decode($jsonString);

// will put *all* scalar and null values into session where key does not begin with a @
foreach($result->addresses->address[0] as $key=>$value) {
    if (substr($key, 0, 1) != '@'  && (is_scalar($value) || is_null($value)) ) {
        $_SESSION[$key] = $value;
    } 
}

print_r($_SESSION);

?>

【讨论】：