如何在php中访问json数组？

I'm using this html and javascript to send json data to my php file. http://jsfiddle.net/ExpertSystem/9aWNj/

How to access it from there in php to echo out a given element?

Something along the lines of:

$value = json_decode($_POST["newOrder"])
echo $value[1];

etc

I'm not sure how to retrieve data from this.

try this :

$value = json_decode($_POST["newOrder"], true)
echo "<pre>";
print_r($value);

Note the second parameter true, that gives you output as array else it will be object.

Check the php manual.

json_decode returns an object as default. use a second param true to return an array.

json_decode($_POST["newOrder"], true)

To use json in PHP like I think you might want to then I suggest you put a true in the json_decode function.

This will give you the following:

$json = json_decode($data,true); 
$json["sub-values"]["sub thing"];

Why to send the JSON as a body of POST request? Do it simpler:

$.ajax({
    url: "<url_to_php_file>",
    type: "POST",
    data: { order: JSON.stringify(dataArr) }
});

And on the server side use:

$value = json_decode($_POST["order"]);
echo $value[1];

Here is a jsfiddle to see how the javascript should be in case you're still lost: http://jsfiddle.net/9aWNj/3/

this is your data decoded by php:

`stdClass Object ( [order] => Array ( [0] => 2 [1] => 3 [2] => 4 [3] => 5 [4] => 6 [5] => 7 [6] => 8 [7] => 9 [8] => 10 [9] => 11 [10] => 1 [11] => 12 ) )`

To access it it will be: example:

 $order_0=$value->order[0];
 $order_1=$value->order[1];

Or you use the true for json_decode and it will become like this

 $order_0=$value['order'][0];
 $order_1=$value['order'][1];

Json_decode return result as object by default, to get array you need to put second parameter to true.

$data = json_decode($_POST["newOrder"], false); return result as object

for printing object use

echo $data->something;

$data = json_decode($_POST["newOrder"], true); return result as array

for printing array use

echo $data['something'];

Try this, It may helpful

$FP=fopen(JSON_DIR."JsonArray.txt",'r');
$J_ARRAY=fread($FP,filesize(JSON_DIR."JsonArray.txt"));
$J_ARRAY=json_decode($J_ARRAY,JSON_FORCE_OBJECT);