如何在从JSON解码的PHP中获取多级数组值

Question

我在PHP中打印数组时遇到问题。我从facebook API获取用户事件的数据并获得JSON结果。

我只想获得每个地点（城市，国家）。有什么方法可以轻松搞定它们吗？

我试过了：

$myjson=json_decode($_POST['Data'],true);
echo "<pre>";
print_r($myjson["data"]);
echo "<pre>";
echo count($myjson["data"]);
echo "<pre>";
for($i =0; $i<count($myjson["data"]); $i++){
    print($myjson["data"][$i]["name"]);
    echo "<br />";
}

当我解码数据并使用print_r：

时

echo "<pre>";
print_r($myjson["data"]);

我得到以下结果：

Array (
    [0] => Array
        (
            [description] => this is test
            [name] => test event Web Developer
            [place] => Array
                (
                    [name] => Lahore
                    [location] => Array
                        (
                            [city] => Lahore
                            [country] => Pakistan
                            [latitude] => 31.5497
                            [longitude] => 74.3436
                        )

                    [id] => 108104849224069
                )

            [start_time] => 2015-10-21T19:00:00+0500
            [id] => 1503962379902466
            [rsvp_status] => attending
        )

    [1] => Array
        (
            [description] => (Full description omitted for brevity)
            [name] => Peaceful Pakistan Online Competition!
            [place] => Array
                (
                    [name] => Punjab Information Technology Board (PITB)
                    [location] => Array
                        (
                            [city] => Lahore
                            [country] => Pakistan
                            [latitude] => 31.5497
                            [longitude] => 74.3436
                            [zip] => 54600
                        )

                    [id] => 340860042630070
                )

            [start_time] => 2015-08-10T00:00:00+0500
            [id] => 907352572664461
            [rsvp_status] => attending
        )

    [2] => Array
        (
            [description] => (Full description omitted for brevity)
            [end_time] => 2015-06-17T19:30:00+0500
            [name] => Open House 2015
            [place] => Array
                (
                    [name] => 6th Floor, Arfa Software Technology Park, 346-B, Ferozepur Road, Lahore, Pakistan-54000
                )

            [start_time] => 2015-06-17T16:30:00+0500
            [id] => 1619010958352625
            [rsvp_status] => attending
        )

    [3] => Array
        (
            [description] => A Two Day Workshop on Game Design and Development on Unity 3d
            [end_time] => 2015-04-26T16:00:00+0500
            [name] => Game Design And Development Workshop
            [place] => Array
                (
                    [name] => House #75, Sarfaraz Rafique Road, Opposite P.A.F Sports Stadium, Lahore Cantt
                )

            [start_time] => 2015-04-26T10:00:00+0500
            [id] => 1651929135026796
            [rsvp_status] => attending
        )

    [4] => Array
        (
            [description] => (Full description omitted for brevity)
            [name] => Live Chat with Experts: How Does Pakistan's Load Shedding Affect You?
            [place] => Array
                (
                    [name] => Islamabad, Pakistan
                )

            [start_time] => 2015-03-26T11:00:00-0400
            [id] => 347677685418059
            [rsvp_status] => attending
        )

    [5] => Array
        (
            [description] => (Full description omitted for brevity)
            [name] => 6th September – Defense Day of Pakistan
            [place] => Array
                (
                    [name] => Virtual Event
                )

            [start_time] => 2013-09-06
            [id] => 434438063339987
            [rsvp_status] => attending
        )

)

Answer 1

基本上你有一个对象数组。由于您强制将JSON解码为数组，因此您有一个数组数组。

从上面示例中的每个对象获取城市/国家非常简单。

foreach($myjson['data'] as $arr) {
    echo $arr['place']['location']['city'], ', ', $arr['place']['location']['country'], "\n";
}

映射到place => location的键提供了一个包含您正在寻找的city和country键的数组。因此，$myjson['data'][$i][place']['location']['city']会为您提供该城市，$myjson['data'][$i][place']['location']['country']会为您提供该国家/地区，但您可以使用$myjson['data']比使用foreach循环更方便地遍历for例如在上面的例子中。

第一个元素会给你Lahore, Pakistan，例如。

Answer 2

foreach($myjson["data"] as $data){
  echo $data['place']['location']['city'];
  echo $data['place']['location']['country'];
}