使用MySQLi和PHP将行分配给变量

I'm just starting to dab into MySQLi after using MySQL for a while. I found this little code snippet on a tutorial, and just had a question about it (since Google won't return any results for me on this...).

<?php 

$link = mysqli_connect("127.0.0.1", "user", "password", "world"); 

if (!$link)
{
    $error = mysqli_connect_error();
    $errno = mysqli_connect_errno();
    print "$errno: $error
";
    exit();
}

$query = "SELECT Name, Population, Continent FROM Country WHERE Continent=? ORDER BY Name LIMIT 1";

$stmt = mysqli_stmt_init($link);
if(!mysqli_stmt_prepare($stmt, $query))
{
    print "Failed to prepare statement
";
}
else
{
    mysqli_stmt_bind_param($stmt, "s", $continent);

    $continent_array = array('Europe','Africa','Asia','North America');

    foreach($continent_array as $continent)
    {
        mysqli_stmt_execute($stmt);
        $result = mysqli_stmt_get_result($stmt);
        while ($row = mysqli_fetch_array($result, MYSQLI_NUM))
        {
            foreach ($row as $r)
            {
                print "$r ";
            }
            print "
";
        }
    }
}
mysqli_stmt_close($stmt);
mysqli_close($link);
?>

Courtesy of http://www.php.net/manual/en/mysqli-stmt.get-result.php

If I'm understanding this correctly then $r will now do an array of all of the results found in all of the rows called. How can I assign a variable to each row? Can I still do something similar like I did in MySQL?

$username = $row['username'];

Or is there something completely different now?