Classmaps

class MyAddress {
    public $country;
    public $city;
    public $full_name;
    public $postal_code; // or zip_code
    public $house_number;
}

class MyBook {
    public $name;
    public $author;

    // The classmap also allows us to add useful functions to the objects
    // that are returned from the SOAP operations.
    public function getShortDescription() {
        return "{$this->name}, written by {$this->author}";
    }
}

$soap_client = new SoapClient($link_to_wsdl, [
    // Other parameters
    "classmap" => [
        "Address" => MyAddress::class, // ::class simple returns class as string
        "Book" => MyBook::class,
    ]
]);

// Lets assume 'getAddress(1234)' returns an Address by ID in the database
$address = $soap_client->getAddress(1234);

// $address is now of type MyAddress due to the classmap
echo $address->country;

// Lets assume the same for 'getBook(1234)'
$book = $soap_client->getBook(124);

// We can not use other functions defined on the MyBook class
echo $book->getShortDescription();

// Any type defined in the WSDL that is not defined in the classmap
// will become a regular StdClass object
$author = $soap_client->getAuthor(1234);

// No classmap for Author type, $author is regular StdClass.
// We can still access fields, but no auto-completion and no custom functions
// to define for the objects.
echo $author->name;