PHP OOP : HOW TO CONNECT TO A DATABASE

<?php

    // database named : ' php_tut '
    // connection to database : Object-Oriented Programming

    class connectDb{

        private $serverNme = "localhost";
        private $dbName = "php_tut";
        private $dbUser = "root";
        private $dbPassword = "";
        private $conn = false;

        function connect(){

            try{
            $this->conn = new PDO("mysql:host=$this->serverNme;dbname=$this->dbName",
                $this->dbUser,$this->dbPassword);

            return $this->conn;

            }catch(PDOException $e){

                echo "error" . $e->getMessage();

            }

        }

        function disconnect(){  // you will need this function later to close connection
            $this->conn = NULL;
            return $this->conn;
        }

    }

    $connection = new connectDb();
    echo $connection->connect();