PHP: Get list of private fields of a class (not instance!)

Question

How can I iterate the private fields of a class without having an instance of it but just the class name? get_object_vars requires an existing instance.

Answer 1

Using: ReflectionClass

you can simply do:

class Foo
{
  public    $public    = 1;
  protected $protected = 2;
  private   $private   = 3;
}

$refClass = new \ReflectionClass('Foo');
foreach ($refClass->getProperties() as $refProperty) {
  if ($refProperty->isPrivate()) {
    echo $refProperty->getName(), "\n";
  }
}

or hide the implementation using a utility function/method:

/**
 * @param string $class
 * @return \ReflectionProperty[]
 */
function getPrivateProperties($class)
{
  $result = [];

  $refClass = new \ReflectionClass($class);
  foreach ($refClass->getProperties() as $refProperty) {
    if ($refProperty->isPrivate()) {
      $result[] = $refProperty;
    }
  }

  return $result;
}

print_r(getPrivateProperties('Foo'));

// Array
// (
//     [0] => ReflectionProperty Object
//         (
//             [name] => private
//             [class] => Foo
//         )
// 
// )