- var_dump: documentation ( source)
- json_decode: documentation ( source)
- array_filter: documentation ( source)
<?php
var_dump(json_decode('{"address": {"address": null, "postalCode": null, "phoneNumber": "", "city": null}}'));
var_dump(array_filter(json_decode('{"address": {"address": null, "postalCode": null, "phoneNumber": "", "city": null}}')));