所以我有一个返回JSON对象的链接，我需要将其解码并放入PHP中的变量中。

网址

api.php?action=getThreads&hash=123fajwersa&node_id=4&order_by=post_date&order=desc&limit=1&grab_content&content_limit=1

这是它返回的对象

{
    "count": 1,
    "threads": {
        "38752": {
            "thread_id": 38752,
            "node_id": 4,
            "title": "The ShadyCraft Beta Launch!",
            "reply_count": 45,
            "view_count": 946,
            "user_id": 2,
            "username": "Shady",
            "post_date": 1366956695,
            "sticky": 0,
            "discussion_state": "visible",
            "discussion_open": 1,
            "discussion_type": "",
            "first_post_id": 226167,
            "first_post_likes": 7,
            "last_post_date": 1369094302,
            "last_post_id": 228226,
            "last_post_user_id": 2,
            "last_post_username": "Shady",
            "prefix_id": 19,
            "tinhte_xentag_tags": "a:4:{i:0;s:9:\"minecraft\";i:2;s:4:\"news\";i:3;s:14:\"private server\";i:1;s:10:\"shadycraft\";}",
            "content": {
                "count": 1,
                "content": {
                    "226167": {
                        "post_id": 226167,
                        "thread_id": 38752,
                        "user_id": 2,
                        "username": "Shady",
                        "post_date": 1366956695,
                        "message": "[ATTACH=full]4143[\/ATTACH]\n \nWe've completely restructured ShadyCraft, and today will be the launch of the ShadyCraft beta.\n \nCurrent Features\n[LIST]\n[*]Towns\n[*]Nations\n[*]All out wars\n[*]A live update map\n[*]No White-list\n[*]Earn Money\n[*]Griefing allowed where possible\n[\/LIST]\nThese are just some features which have a lot more things behind them. For instance, there is town and nation upkeep, tax, kingdoms, mayors, and kings.\n \nWe really wanted to have the server self-governed and this is why griefing and PvP are allowed where ever they are possible. All towns and nations cannot be griefed by other members. You can create a town and buy plots for it and expand the town as you wish.\n \n[SIZE=4]All of this is shown in the live updating map located [URL='http:\/\/50.7.6.116:8123']here[\/URL].[\/SIZE]\n \n[SIZE=4][SIZE=6]Join the Beta Now[\/SIZE][\/SIZE]\n[SIZE=6]Server-IP: 50.7.6.116[\/SIZE]\n \n \n[USER=118053]Frenchy[\/USER] and [USER=4863]Wolfbane[\/USER]",
                        "ip_id": 747429,
                        "message_state": "visible",
                        "attach_count": 1,
                        "position": 0,
                        "likes": 7,
                        "like_users": "a:5:{i:0;a:2:{s:7:\"user_id\";i:105699;s:8:\"username\";s:6:\"kvothe\";}i:1;a:2:{s:7:\"user_id\";i:146724;s:8:\"username\";s:12:\"Graveyard219\";}i:2;a:2:{s:7:\"user_id\";i:70182;s:8:\"username\";s:9:\"wmbrown18\";}i:3;a:2:{s:7:\"user_id\";i:5473;s:8:\"username\";s:9:\"Oblivious\";}i:4;a:2:{s:7:\"user_id\";i:118053;s:8:\"username\";s:7:\"Frenchy\";}}",
                        "warning_id": 0,
                        "warning_message": "",
                        "anonymous_posting_real_user_id": 0,
                        "anonymous_posting_real_username": ""
                    }
                }
            }
        }
    }
}

我真的只对

"title":"The ShadyCraft Beta Launch!",  
"reply_count:"45, 
"view_count": 946,  
"user_id":2, 
"username":"Shady", 
"post_date":1366956695, 
"sticky":0, 
"discussion_state":"visible",
"discussion_open":1,

最后，

[ATTACH=full]4143[/ATTACH]

We've completely restructured ShadyCraft, and today will be the launch of the ShadyCraft beta.

Current Features
[LIST]
[*]Towns
[*]Nations
[*]All out wars
[*]A live update map
[*]No White-list
[*]Earn Money
[*]Griefing allowed where possible
[/LIST]
These are just some features which have a lot more things behind them. For instance, there is town and nation upkeep, tax, kingdoms, mayors, and kings.

We really wanted to have the server self-governed and this is why griefing and PvP are allowed where ever they are possible. All towns and nations cannot be griefed by other members. You can create a town and buy plots for it and expand the town as you wish.

[SIZE=4]All of this is shown in the live updating map located [URL='http://50.7.6.116:8123']here[/URL].[/SIZE]

[SIZE=4][SIZE=6]Join the Beta Now[/SIZE][/SIZE]
[SIZE=6]Server-IP: 50.7.6.116[/SIZE]

[USER=118053]Frenchy[/USER] and [USER=4863]Wolfbane[/USER]

那么，我如何提取JSON对象并将其放入PHP中以纠正变量，以便以后使用？
变量如：$username、$user_id、$message、$title、$discussionState等等。

我只需要知道如何检索JSON对象，然后将数据提取到PHP变量中。

我现在可以得到PHP数组了，但是在调用正确的值时遇到了一些问题。这里是数组。
Array（[count] => 1 [threads] => Array（[13] => Array（[thread_id] => 13 [node_id] => 4 [title] =>论坛集成即将完成！[回复数量] => 0 [查看数量] => 0 [用户ID] => 59 [用户名] => Faeron [发布日期] => 1369257302 [粘性] => 0 [讨论状态] =>可见[讨论打开] => 1 [讨论类型] => [第一个帖子ID] => 23 [第一个帖子喜欢] => 0 [最后一个帖子日期] => 1369257302 [last_post_id] => 23 [last_post_user_id] => 59 [last_post_username] => Faeron [prefix_id] => 1 [content] => Array（[count] => 1 [content]=> Array（[23] => Array（[post_id] => 23 [thread_id] => 13 [user_id] => 59 [username] => Faeron [post_date] => 1369257302 [message] =>自从我们开始将phanime论坛与主站点整合以来，已经有相当长的一段时间了。我们现在已经完成了与phanime论坛和主网站的整合。您将不再注意到有两个平台运行phanime，而是只有一个。我们的下一步是主题的论坛，使它看起来像主网站！[IP_ID] => 268 [消息状态] =>可见[attach_count] => 0 [位置] => 0 [喜欢] => 0 [喜欢_用户] => a：0：{} [警告_ID] => 0 [警告_消息] =>）
现在让我们假设这个数组名为$array，那么要获取第一个元素的值“[count]”，我不能只说下面的话：print $array["[count]"] <--返回错误。
那么本身具有数组值的元素，也就是[threads]元素呢？如何获取[thread_id]元素的值？