How to loop my data for PHP - php

Question

I have some data which was json decoded and looks like this:
stdClass Object
(
[6] => stdClass Object
(
[13] => stdClass Object
(
[buildingId] => 1
)
)
[8] => stdClass Object
(
[20] => stdClass Object
(
[Id] => 1
)
)
Thing is i don't know how to loop to get the information to use it in my script.
I need to get for example:
$key, $innerkey, $Id = 1
Object [8][20].Id = 1
The two numbers are X;Y co ordinates so its important i get those values aswell as the id.
I managed to get the first key:
$obj = JSON_decode($_GET['data']);
foreach($obj as $key) {
echo $key;
}
How do i get the innerkey assigned to a variable ?

Answer 1

Change json_decode($_GET['data']); to json_decode($_GET['data'], true);
If the second parameter is true then it return the array else it is object.
$obj = json_decode($_GET['data'], true);
foreach($obj as $key=>$val) {
foreach($val as $k=>$v){
echo $k." : ".$v['Id'];
echo "<br>";
}
}
Ref: http://php.net/manual/en/function.json-decode.php

Answer 2

You need to wrap numeric keys with {}. Kind of a PHP caveat.
echo $obj->{8}->{20}->Id;

Answer 3

Do you mean this?
$array = (array)json_decode($_GET['data']);
foreach ($array as $key) {
var_dump($key);
}
or
$array = json_decode($_GET['data'], true);
foreach ($array as $key) {
var_dump($key);
}
json_decode()'s 2. parameter: true: to array, false: to object.

Answer 4

You have to use two foreach loops for this as below
$obj = JSON_decode($_GET['data']);
foreach($obj as $key) {
foreach($key as $val) {
echo $val->id;
}
}
updated answer
$obj->{8}->{20}->Id = 10; // assigned the value for testing purpose.
$a = 8;
$b = 20;
echo $obj->$a->$b->Id;