MAMP & MAMP PRO 4 Documentation

$user = 'root';
$password = 'root';
$db = 'inventory';
$host = 'localhost';
$port = 8889;

$link = mysqli_init();
$success = mysqli_real_connect(
   $link, 
   $host, 
   $user, 
   $password, 
   $db,
   $port
);

$user = 'root';
$password = 'root';
$db = 'inventory';
$host = '127.0.0.1';
$port = 8889;
$socket = 'localhost:/Applications/MAMP/tmp/mysql/mysql.sock';

$link = mysqli_init();
$success = mysqli_real_connect(
   $link, 
   $host,
   $user, 
   $password, 
   $db,
   $port,
   $socket
);