如何通过解码的JSON类中的反射访问数字属性？

Question

Here is the object I decode from JSON in PHP:

php > var_dump($v);
object(stdClass)#9 (1) {
  ["objects"]=>
  object(stdClass)#10 (2) {
    ["16"]=>
    object(stdClass)#14 (2) {
      ["id"]=>
      int(16)
      ["name"]=>
      string(8) "Object 1"
    }
    ["32"]=>
    object(stdClass)#11 (2) {
      ["id"]=>
      int(20)
      ["name"]=>
      string(8) "Object 2"
    }
  }
}
php > $rc = new \ReflectionClass($v);
php > var_dump($rc);
object(ReflectionClass)#17 (1) {
  ["name"]=>
  string(8) "stdClass"
}
php > var_dump($rc->getProperties());
array(0) {
}

As you can see, ReflectionClass fails to detect any of the properties. I cannot do $v->objects->32, because PHP does not allow numeric properties. I also cannot decode to an associative array, because that would break JSON handling in other parts of my system.

Answer 1

The simpliest way is to use the second parameter of json_decode and set it to true. Using this method, you can access the vars like in any other associative array

$v = json_decode($data, true);
$value = $v['objects']['32']

if you cant change the json_decode call, you can use the following syntax to access the var

$v = json_decode('{"objects":{"16":{"id":16,"name":"Object 1"},"32":{"id":20,"name":"Object 2"}}}');
var_dump($v->objects->{'16'});

and even

$name = '16';
var_dump($v->objects->{$name});