how to print base url in codeigniter code example

Example 1: codeigniter base_url

$this->load->helper('url');

Example 2: codeigniter base url automatic

$base_url = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == "on") ? "https" : "http");
$base_url .= "://". @$_SERVER['HTTP_HOST'];
$base_url .=     str_replace(basename($_SERVER['SCRIPT_NAME']),"",$_SERVER['SCRIPT_NAME']);
$config['base_url'] = $base_url;