PDO with classes

So i am trying to make connect to a database. However, I am running into the issue of grabbing strings to connect to the database. First one fails, second one is successful.

PHP Code:

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class dbedits {
    private $pdo = null;
    private $servername = "localhost";
    private $dbusername = "root";
    private $dbpassword = "";

    public function dbconnect($dbname){

        try{
            $this->$pdo = new PDO("mysql:host=".$this->servername, $this->$dbusername, $this->$dbpassword);
            $this->$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $dbname = "`".str_replace("`","``",$dbname)."`";
            $this->$pdo->query("CREATE DATABASE IF NOT EXISTS $dbname");
            $this->$pdo->query("use $dbname");
        }catch(PDOException $e){
            echo $e->getMessage();
        }
    }

    public function dbcreate($dbname){            
        //$this->dbconnect($dbname);
        try{
            $pdo = new PDO("mysql:host=".$this->servername, "root","");
            $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $dbname = "`".str_replace("`","``",$dbname)."`";
            $pdo->query("CREATE DATABASE IF NOT EXISTS $dbname");
            $pdo->query("use $dbname");
        }catch(PDOException $e){
            echo $e->getMessage();
        }
    }
} 


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I fixed it. I forgot to remove the '$' top ones.

PHP Code:

---

public function dbconnect($dbname){ 

        try{ 
            $this->pdo = new PDO("mysql:host=".$this->servername, $this->dbusername, $this->dbpassword); 
            $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 
            $dbname = "`".str_replace("`","``",$dbname)."`"; 
            $this->pdo->query("CREATE DATABASE IF NOT EXISTS $dbname"); 
            $this->pdo->query("use $dbname"); 
        }catch(PDOException $e){ 
            echo $e->getMessage(); 
        } 
    } 


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