What are the potential pitfalls when switching from PHP 4 to PHP 5 in terms of object handling?

When switching from PHP 4 to PHP 5 in terms of object handling, one potential pitfall is the change in the visibility of properties and methods. In PHP 5, the visibility keywords (public, protected, private) were introduced, which may cause issues if the code relies on accessing private properties or methods directly. To solve this, update the code to use proper visibility keywords and access properties and methods through getter and setter methods.

class MyClass {
    private $myProperty;

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

    public function setMyProperty($value) {
        $this->myProperty = $value;
    }
}

$obj = new MyClass();
$obj->setMyProperty('value');
echo $obj->getMyProperty();