note 130035 added to language.oop5.property-hooks

The json_encode() function returns false when trying to serialize an object that contains a property with only a set hook, but without a get hook, because the function seeks to get the property value from the get hook and returns false if no such hook has been defined. The following example shows how, when serializing an object with the json_encode() function, to get an empty serialized object, or object with only initialized and only public properties instead of false; the restriction is—the object must remain empty and not set the uninitialized properties to null: <?php class Lambic // Implementing an interface to intercept json_encode() serialization implements JsonSerializable { // Note: The property with the set hook only /** @var int It must be typed if need to omit an uninitialized property in output object */ public int $age { set => $value; } /** * Implements the interface method */ #[Override] public function jsonSerialize(): stdClass { // Cast the array to an object to get an empty serialized object when object does not contain initialized properties return (object) get_mangled_object_vars($this); } public function __construct(?int $age = null) { if ($age !== null) { $this->age = $age; } } } // Get the empty serialized object without properties $noagedLambic = new Lambic(); var_dump(json_encode($noagedLambic)); // {} and not {"age":null} // ...and with properties if initialized $agedLambic = new Lambic(20); var_dump(json_encode($agedLambic)); // {"age":20} ?> ---- Server IP: 45.112.84.4 Probable Submitter: 80.90.5.137 (proxied: 95.25.91.102) ---- Manual Page -- https://php.net/manual/en/language.oop5.property-hooks.php Edit -- https://main.php.net/note/edit/130035 Del: integrated -- https://main.php.net/note/delete/130035/integrated Del: useless -- https://main.php.net/note/delete/130035/useless Del: bad code -- https://main.php.net/note/delete/130035/bad+code Del: spam -- https://main.php.net/note/delete/130035/spam Del: non-english -- https://main.php.net/note/delete/130035/non-english Del: in docs -- https://main.php.net/note/delete/130035/in+docs Del: other reasons-- https://main.php.net/note/delete/130035 Reject -- https://main.php.net/note/reject/130035 Search -- https://main.php.net/manage/user-notes.php