Codeigniter :Use of undefined constant

Question

This is my Model:

class Medecin_model extends CI_Model
{
    public $fillable = array('nom','prenom','genre','adresse','date_naissance','specialiter','servise','grade','etablissement','type_personne');
    public $id_medecin;
    public $nom;
    public $prenom;
    public $genre;
    public $adresse;
    public $date_naissance;
    public $specialiter;
    public $service;
    public $grade;
    public $etablissement;
    public $type_personne = Medecin;
    public function insert($nom, $prenom, $genre, $adresse, $date_naissance, $specialiter, $service, $grade, $etablissement)
    {
        $this->nom=$nom;
        $this->prenom=$prenom;
        $this->genre=$genre;
        $this->adresse=$adresse;
        $this->date_naissance=$date_naissance;
        $this->specialiter=$specialiter;
        $this->service=$service;
        $this->grade=$grade;
        $this->etablissement=$etablissement;
        // $this->db->insert('personne', $this);
    }

This is my controller:

defined('BASEPATH') OR exit('No direct script access allowed');

class Medecin extends CI_Controller
{

    public function index()
    {
        $this->load->view('header');
        $this->load->view('ajout_medecin');
        $this->load->view('footer');


    }
    public function ajout()
    {
        $this->load->model("Medecin_model");
        $nom=$this->input->post('first-name');
        $prenom=$this->input->post('last-name');
        $genre=$this->input->post('genre');
        $adresse=$this->input->post('adress');
        $date_naissance=$this->input->post('birthday');
        $specialiter=$this->input->post('speciality');
        $service=$this->input->post('service');
        $grade=$this->input->post('grade');
        $etablissement=$this->input->post('establishment');

        $doctor = new Medecin_model();
        $doctor->insert($nom, $prenom, $genre, $adresse, $date_naissance, $specialiter, $service, $grade, $etablissement);
    }

and i have this error message :

A PHP Error was encountered Severity: Notice Message: Use of undefined constant Medecin - assumed 'Medecin' Filename: core/Loader.php Line Number: 357 Backtrace: File: C:\wamp64\www\CodeIgniter\application\controllers\Medecin.php Line: 23 Function: model File: C:\wamp64\www\CodeIgniter\index.php Line: 315 Function: require_once

Answer 1

Missing '' around Medecin

Replace it

public $type_personne = Medecin; 

With this

public $type_personne = 'Medecin';