Better iteration to display Object properties PHP

I'm looking for a better way to iterate through an object and display its contents.
FormController:

   public function run(){

        $tabteachers='';

        if(!empty($_SESSION['apply']) && !empty($_SESSION['application'])){

            $tabteachers = DB::getInstance()->select_teacher_id($_SESSION['login']);
        }
        require_once(VIEW_PATH.'formdeux.php'); 
    }

Db.class function():

public function select_teacher_id($login){
        $query = 'SELECT * FROM teachers,internships,students WHERE teachers.email_teacher = internships.email_responsible_internship AND students.registry_number_student = internships.registry_student_internship AND internships.registry_student_internship = '. $this->_db->quote ( $login );
        $result = $this->_db->query ( $query );
        if ($result->rowcount () != 0) {
            while ( $row = $result->fetch () ) {
                $teacher[]= new teacher ( $row->email_teacher,$row->firstname_teacher,$row->lastname_teacher,$row->responsible_internship_teacher,NULL);
            }

            return $teacher;
        }
    }

Form View:

    





















        
            
                
contact
            
        
            
                            
                    
Lastname: 

                    
                
                
                    
Firstname: 


                    
                
                
                    
Email address: 

                    
                
                
                    
Service: 

                    
                
                
                    
mobile number: 

                    
                
                        
    

Db connection:

private static $instance = null;
    private $_db;

    private function __construct() {

        try {
            $this->_db = new PDO ('mysql:host=localhost;dbname=ProjectWeb;charset=utf8', 'root', '' );
            $this->_db->setAttribute ( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
            $this->_db->setAttribute ( PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ );


        } catch ( PDOException $e ) {
            die ( 'Erreur de connexion à la base de donnée : ' . $e->getMessage () );
        }
    }

    // Pattern Singleton
    public static function getInstance() {
        if (is_null ( self::$instance )) {
            self::$instance = new Db ();

        }
        return self::$instance;
    }

thanks for your help in advance!

Answer

I see you have set the default fetch mode to FETCH_OBJ , in this particular case though I think you can rather get the entire result set as an array using PDO's fetchAll method and then iterate though it,

 public function select_teacher_id($login){
   $query = 'SELECT * FROM teachers,internships,students WHERE

   teachers.email_teacher = internships.email_responsible_internship
  AND students.registry_number_student = internships.registry_student_internship
  AND internships.registry_student_internship = '. $this->_db->quote ( $login );


   $result = $this->_db->query ( $query );
       if ($result->rowcount () != 0) {
         //fetch the entire result set as a multi-dimensional assoc array
         $teachers_result = $result->fetchAll(PDO::FETCH_ASSOC); 
         return $teachers_result;

       }
 }

// VIEW

    
        
            
contact
        
    
        
                    
                
Lastname: 

                
            
            
                
Firstname: 


                
            
            
                
Email address: 

                
            
            
                
Service: 

                
            
            
                
mobile number: