There is an array. Each element of the array is an object with two fields.
Example

[{"type": "photo", "photo": {photo}}, {"type": "audio", "audio": {audio}}]

How can I get the object fields from this: type and photo (or audio, no difference)?

$ a [‘type’] doesn’t work

Answer 1

Something like this:

$ obj_array = json_decode ('[{"type": "photo", "photo": {"some" : "content"}}, {"type": "audio", "audio": {"some": "content"}}] ');
print_r ($ obj_array);
$ reult = array ();
  foreach ($ obj_array as $ obj) {
    $ type = $ obj- & gt; type;
    $ reult [$ obj- & gt; type] = $ obj- & gt; $ type;
  }
print_r ($ reult);

Output:

Array
(
  [0] = & gt; stdClass Object
    (
      [type] = & gt; photo
      [photo] = & gt; stdClass Object
        (
          [some] = & gt; content
        )
    )
  [1] = & gt; stdClass Object
    (
      [type] = & gt; audio
       = & gt; stdClass Object
        (
          [some] = & gt; content
        )
    )
)
Array
(
  [photo] = & gt; stdClass Object
    (
      [some] = & gt; content
    )
   = & gt; stdClass Object
    (
      [some] = & gt; content
    )
)

Answer 2

Did you give this line just for demonstration?
In general, object properties are accessed like this:

$ a- & gt; type

Accordingly from an array

$ ar [0] - & gt; type