php类

<?php
class DBConnection{
function connect(){
$conn = $this->createDBConnection();
return $conn;
}
protected function createDBConnection(){
$mysql_server_name='127.0.0.1';
$mysql_username='root';
$mysql_password='123456';
$mysql_database='mysql';
return mysql_connect($mysql_server_name,$mysql_username,$mysql_password,$mysql_database);
}
}
$db = new DBConnection();
$conn = $db->connect();
echo $conn;
?>