How does the design of PHP classes impact the overall structure and organization of a project?

The design of PHP classes can greatly impact the overall structure and organization of a project. By properly designing classes with clear responsibilities and relationships, you can create a more maintainable and scalable codebase. This can lead to easier debugging, testing, and future enhancements.

class User {
    private $id;
    private $username;
    
    public function __construct($id, $username) {
        $this->id = $id;
        $this->username = $username;
    }
    
    public function getId() {
        return $this->id;
    }
    
    public function getUsername() {
        return $this->username;
    }
}