public function safeData()
    {
        if(!isset($this->user))
            return $result = "Данные не поступили!";
        else
        {
            $this->user = htmlspecialchars(addslashes($this->user));
            return $this->user;
        }    
          
    }

  class DBConnection
  {
    public $host = "localhost";
    public $user = "root";
    public $password = "";
    public $db = "names";
    protected $link;
    protected $selectDB;
    
    public function __construct()
    {   
        $this->host = $host;
        $this->user = $user;
        $this->password = $password;
        $this->db = $db;
        $this->link = $link;
        $this->selectDB = $selectDB;
    }
    
    public function connect()
    {
        $this->link = mysql_connect($this->host, $this->user, $this->password);
        
        if(!$this->link)
            return mysql_error();
        
        $this->selectDB = mysql_select_db($this->db);

        if(!$this->selectDB)
            return mysql_error();
             
    }

  }

      $obj = new DBConnection;
      $obj->connect();

    // Эти я хотел заполнять при инициализации объекта.
    public $host = "localhost";
    public $user = "root";
    public $password = "";
    public $db = "names";
    //Их я собираю потом использовать в другом классе через extented
    protected $link;      
    protected $selectDB;

<?php

class DB {

    //simple singleton for db connection
    private static $dbconfig = array();
    protected static $instance = null;
    private $dblink = null;

    /**
     * @return DB 
     */
    public static function getInstance()
    {
        if (is_null(self::$instance))
        {
            self::$instance = new DB();
        }
        return self::$instance;
    }

    private function __construct()
    {
        self::$dbconfig = CONFIG::getInstanse()->getGroupConfig('db');
        try
        {
            $this->dblink = new PDO('mysql:host=' . self::$dbconfig['host'] . ';dbname=' . self::$dbconfig['dbname'], self::$dbconfig['user'], self::$dbconfig['pass']);
            $this->dblink->exec('SET NAMES \'utf8\'');
        } catch (PDOException $e)
        {
            echo 'Connection failed: ' . $e->getMessage();
            exit;
        }
    }
    /**
     * @return PDO 
     */
    public function getPdoInstanse()
    {
        return $this->dblink;
    }

    /**
     *
     * @param string $sql
     * @return PDOStatement 
     */
    public function query($sql)
    {
        try
        {
            return $this->dblink->query($sql);
        } catch (PDOException $e)
        {
            echo 'Query failed: ' . $e->getMessage();
            exit;
        }
    }

    public function exec($sql)
    {
        try
        {
            return $this->dblink->exec($sql);
        } catch (PDOException $e)
        {
            echo 'Exec failed: ' . $e->getMessage();
            exit;
        }
    }
    
    /**
     * @return PDOStatement 
     */
    public function prepare($sql)
    {
         return $this->dblink->prepare($sql);
    }

    private function __clone()
    { /* nonono david blaine,nonono! */
    }

    private function __wakeup()
    { /* same */
    }

}

?>