How do I access nested arrays from a json_decode i

问题:

I have spent hours at this and I've read loads of answers here on stackoverflow and none have helped.

All I've been able to do so far is to print Market Square - Clifden for this example.

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

I can't figure out how to access "name" nested inside "image" so I can get market_square_clifden.jpg.

I'd be grateful for some pointers.

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)""
                }
            }
        }
    }

回答1:

As the commenters mentioned, please fix your variable formatting - it helps get answers more quickly.

Assuming you are using default json_decode settings, each JSON object will become a PHP object. (See the json_decode documentation at php.net.)

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

If you force everything to be associative arrays:

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

回答2:

You can get it using the code below. You can think of all arrays as dictionaries or associated arrays in php. Either They are indexed by numbers (regular array) or they are indexed by keys (associated arrays).

$obj[0]["image"]["name"]

In the instance of nested arrays, when you access the inner array, you can treat that as if it were an array. Think of it like this:

$innerArray = $obj[0];
// The image key gives us an array as well.
$image = $innerArray["image"];
// Now we have the dictionary where the name is
$name = $image["name"];