从class - php访问属性

class MyClass {
    public $myProperty = "Hello World!";
}

$obj = new MyClass();
echo $obj->myProperty; // 输出：Hello World!

class MyClass {
    protected $myProperty = "Hello World!";
}

class MyChildClass extends MyClass {
    public function getMyProperty() {
        return $this->myProperty;
    }
}

$obj = new MyChildClass();
echo $obj->getMyProperty(); // 输出：Hello World!

class MyClass {
    private $myProperty = "Hello World!";

    public function getMyProperty() {
        return $this->myProperty;
    }
}

$obj = new MyClass();
echo $obj->getMyProperty(); // 输出：Hello World!