Connect to a MySQL database with PHP using PDO and MySQLi

gistfile1.php

<?php
// Be sure to input YOUR database details below
// Watch the associated videos here: https://www.youtube.com/playlist?list=PLLs69n7Q4dCx5_7ZwnxTymH8X0iRP_2vw

$db_user = 'DB USERNAME HERE';
$db_pass = 'DB PASSWORD HERE';
$db_name = 'DB NAME HERE';
$db_host = 'localhost';

//MySQLi
$mysqli = new mysqli($db_host, $db_user, $db_pass, $db_name);

if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

$result->close();

// PDO
//try {
//    $conn = new PDO("mysql:host={$db_host};dbname={$db_name}", $db_user, $db_pass);
//    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
//} catch(PDOException $e) {
//    echo 'ERROR: ' . $e->getMessage();
//}