class User { private $firstname; private $lastname; public function __construct($firstname, $lastname) { $this->firstname = $firstname; $this->lastname = $lastname; } public function getFullName() { return $this->firstname . ' ' . $this->lastname; } } $user = new User('John', 'Doe'); echo $user->getFullName();In the above example, a User class is defined with two private properties - firstname and lastname. The getFullName() function is also defined within the class, which combines the firstname and lastname properties and returns the full name of the user. An instance of the User class is created, and the getFullName() function is called using an echo statement to print the full name to the output. There is no specific package or library associated with the getFullName() function as it is a simple function that can be written and used within any PHP application.