未知属性上的未定义属性

Question

i work on a little project in php, i have make this clas for BDD connection but i have a problem :

here
Notice: Undefined variable: dataBase in /home/alban/Bureau/project/web/concessionnaire-auto.com/www/modele/BDD.php on line 29

Notice: Undefined property: BDD::$ in /home/alban/Bureau/project/web/concessionnaire-auto.com/www/modele/BDD.php on line 29

Fatal error: Uncaught Error: Call to a member function prepare() on null in /home/alban/Bureau/project/web/concessionnaire-auto.com/www/controller/UserController.php:8 Stack trace: #0 /home/alban/Bureau/project/web/concessionnaire-auto.com/www/index.php(20): UserController::addUser() #1 {main} thrown in /home/alban/Bureau/project/web/concessionnaire-auto.com/www/controller/UserController.php on line 8

Here is the code :

<?php
class BDD
{
    private $dataBase;

    private static $instance;

    private function __construct()
    {
        $db="web";
        $dbhost="localhost";
        $dbport=3306;
        $dbuser="web";
        $dbpasswd="web";

        try {
            echo "here\n";
            $this->dataBase = new PDO('mysql:host='.$dbhost.';port='.$dbport.';dbname='.$db.'', $dbuser, $dbpasswd);
        } catch (PDOException $e) {
            die("erreur de connexion :" . $e->getMessage());
        }
    }

    public static function getBDD() {
        if(!isset(self::$instance)){
            self::$instance = new BDD();
        }
        return (self::$instance)->$dataBase;
    }
}

But i dont understand what i'm doing wrong.

Answer 1

将(self::$instance)->$dataBase替换为(self::$instance)->dataBase