php - 如何从 PHP 中的 json_decode 访问嵌套数组？

Question

我在这上面花了几个小时，我在 stackoverflow 上阅读了大量答案，但没有一个有帮助。

到目前为止，我所能做的就是为这个例子打印Market Square - Clifden。

$obj = json_decode($data);
$obj = $obj[0];
print $obj->{'title'};

我不知道如何访问嵌套在“图像”中的“名称”，以便我可以获得 ma​​rket_square_clifden.jpg。

我将不胜感激。

array(1){
        [0]=>array(12){
            ["_id"]=>array(1){
                ["$oid"]=>string(24)"51f674e4e4b0066cc8197033"
            }
            ["display"]=>int(1)
            ["title"]=>string(23)"Market Square - Clifden"
            ["class"]=>string(21)"market_square_clifden"
            ["icon"]=>string(16)"camera_small.png"
            ["image"]=>array(4){
                ["name"]=>string(25)"market_square_clifden.jpg"
                ["top"]=>string(16)"7.98958587646484"
                ["left"]=>string(18)"397.98614501953125"
                ["maxwidth"]=>string(16)"599.777777671814"
            }
            ["locs"]=>array(2){
                ["lng"]=>float(-10.022516)
                ["lat"]=>float(53.488111)
            }
            ["pov"]=>array(3){
                ["heading"]=>string(17)"-14.1950626239811"
                ["pitch"]=>string(18)"-6.368221166504443"
                ["zoom"]=>string(18)"0.8399999999999999"
            }
            ["photo"]=>array(3){
                ["takenby"]=>string(13)"Robert French"
                ["sentinby"]=>string(34)"The Lawrence Photograph Collection"
                ["description"]=>string(263)"Clifden (Irish: An Clochán, meaning 'stepping stones' is a town on the coast of County Galway, Ireland and being Connemara's largest town, it is often referred to as 'the Capital of Connemara'. It is located on the Owenglen River where it flows into Clifden Bay."
            }
            ["date"]=>array(2){
                ["posted"]=>string(53)"Mon Jul 29 2013 14:53:53 GMT+0100 (GMT Daylight Time)"
                ["circa"]=>string(9)"1880-1900"
            }
            ["comments"]=>array(1){
                [0]=>array(2){
                    ["poster"]=>string(0)""
                    ["comment"]=>string(0)""
                }
            }
            ["tags"]=>array(1){
                [0]=>array(2){
                    ["name"]=>string(0)""
                    ["slug"]=>string(0)""
                }
            }
        }
    }

Answer 1

正如评论者所提到的，请修复您的变量格式 - 它有助于更​​快地获得答案。

假设您使用默认的 json_decode 设置，每个 JSON 对象将成为一个 PHP 对象。 (参见 php.net 上的 the json_decode documentation。)

$obj = json_decode($data);
$obj = $obj[0];
// title attribute
$obj->title
// image object
$obj->image
// image name
$obj->image->name

如果你强制一切都成为关联数组:

$obj = json_decode($data,true);
$obj = $obj[0];
// title attribute
$obj['title']
// image object
$obj['image']
// image name
$obj['image']['name']