Json_decode处理数组和对象 - json_decode deals with arrays and objects

json_decode deals with arrays and objects

本文关键字：对象数组处理 decode Json | 更新日期: 2023-09-27

下面是我创建的函数，通过cURL认证获取Delicious最近的书签，然后进行XML->JSON转换:

<?php
// JSON URL which should be requested
$json_url = 'https://api.del.icio.us/v1/posts/recent';
$username = 'myusername';  // authentication
$password = 'mypassword';  // authentication
// Initializing curl
$ch = curl_init( $json_url );
// Configuring curl options
$options = array(
CURLOPT_RETURNTRANSFER => true,
CURLOPT_USERPWD => $username . ":" . $password   // authentication
);
// Setting curl options
curl_setopt_array( $ch, $options );

$cache_delicious = '/BLAHBLAH/'.sha1($json_url).'.json';
    if(file_exists($cache_delicious) && filemtime($cache_delicious) > time() - 1000){
        // if a cache file newer than 1000 seconds exist, use it
        $data_delicious = file_get_contents($cache_delicious);
    } else {
        $delicious_result = simplexml_load_string(curl_exec($ch));
        $data_delicious = json_encode($delicious_result);
        file_put_contents($cache_delicious, $data_delicious);
    }
$obj = $data_delicious['post']['@attributes'];
foreach (array_slice(json_decode($data_delicious, true), 0, 5) as $obj) {
    $delicious_title = str_replace('"', '''', $obj['description']);
    $delicious_url = htmlentities($obj['href'], ENT_QUOTES, "UTF-8");
    $output = "<li><a rel='"external nofollow'" title='"$delicious_title'" href='"$delicious_url'">$delicious_title</a></li>";
    echo $output;
}
?>

如果我执行print_r($data_delicious);这是JSON，为了可读性，只减少到一个条目:

{
   "@attributes":{
      "tag":"",
      "user":"myusername"
   },
   "post":[
      {
         "@attributes":{
            "description":"Fastweb: fibra o VDSL? Disinformazione alla porta",
            "extended":"",
            "hash":"d00d03acd6e01e9c2e899184eab35273",
            "href":"http:'/'/storify.com'/giovannibajo'/fastweb-fibra-o-vdsl",
            "private":"no",
            "shared":"yes",
            "tag":"",
            "time":"2013-06-14T10:30:08Z"
         }
      }
   ]
}

不幸的是，foreach中的变量($delicious_title和$delicious_url)有问题，因为我得到未定义的索引:描述和href.

尝试使用json-last-error

捕获错误

如果您阅读json_decode的手册，您可以看到第二个参数。如果将其设置为true，则输出将是一个数组。所以只要使用array_slice(json_decode($data_delicious, true), 0, 5)。

最好事先进行一些错误检查。

<?php
$result = json_decode($data_delicious, true);
if (is_array($result)) {
  foreach (array_slice($result, 0, 5) as $obj) {
    $delicious_title = str_replace('"', '''', $obj->description);
    $delicious_url = htmlentities($obj->href, ENT_QUOTES, "UTF-8");
    $output = "<li><a rel='"external nofollow'" title='"$delicious_title'" href='"$delicious_url'">$delicious_title</a></li>";
    echo $output;
  }
}
?>

错误明确

your variable obj is undefined

试试这个

$obj_delicious = json_decode($data_delicious, true); 
foreach (array_slice($obj_delicious, 0, 5) as $obj)
    {        $delicious_title = str_replace('"', '''', $obj['post']['@attributes']['description']);
            $delicious_url = htmlentities($obj['post']['@attributes']['href'], ENT_QUOTES, "UTF-8");
            $output = "<li><a rel='"external nofollow'" title='"$delicious_title'" href='"$delicious_url'">$delicious_title</a></li>";
            echo $output;
    }
        }