mysqli::real_connect(): (HY000/1045): Access denied for user 'root'@' code example

Example 1: mysqli::real_connect(): (HY000/1045): Access denied for user 'pma'@'localhost' (using password: NO)

$cfg['Servers'][$i]['port'] = '3307';

Example 2: mysqli_real_connect(): (28000/1045): Access denied for user 'u0738423'@'www8.aname.net' (using password: YES)

// Connect to mysqli database

$connection = mysqli_connect('localhost', 'root', '', 'test'); 

// OR with a P@$$w0rd

$connection = mysqli_connect('localhost', 'root', 'P@$$w0rd', 'test');