unet900

class A {
    public $str;

    public function getStr()
    {
        return $this->str;
    }

    public function setStr($str)
    {
        $this->str = $str;
    }
}

$a = new A();
$a->setStr('New value');
var_dump($a->getStr()); // New value
$a = new A();
var_dump($a->getStr()); // null