PHP Magic Method __isset() and __unset()

index.php

<?php 

class Dog {
	public $data = [];


	public function __set($property, $value) {
		$this->data[$property] = $value;		
	}

	public function __isset($property) {
		echo "isset triggered! <br>";
		return isset($this->data[$property]);
	}

	public function __unset($property) {
		echo "unset triggered! <br>";
		unset($this->data[$property]);
	}

}

$dog = new Dog();
var_dump(isset($dog->color));
$dog->color = "Black";
var_dump(isset($dog->color));
unset($dog->color);
var_dump(isset($dog->color));

?>