In what ways can outdated or deprecated functions, like "$mysql_connect", impact a beginner's understanding of PHP?

Using outdated or deprecated functions like "$mysql_connect" can impact a beginner's understanding of PHP by teaching them bad practices and potentially leading to insecure code. It's important for beginners to learn and use modern, secure functions like "mysqli_connect" or PDO for interacting with databases in PHP.

// Correct way to connect to a MySQL database using mysqli_connect
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = mysqli_connect($servername, $username, $password, $dbname);

if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}