PHP 7.2 - Warning: count(): Parameter must be an array or an object that implements Countable

Question

I just upgraded my PHP installation from version 5.6 to 7.2. I used the count() function on my login page like so:

if (!empty($_POST['username']) && !empty($_POST['password'])):
    $records = $conn->prepare('SELECT id,username,password FROM users WHERE username = :username');
    $records->bindParam(':username', $_POST['username']);
    $records->execute();
    $results = $records->fetch(PDO::FETCH_ASSOC);

    $message = '';
    
    if (count($results) > 0 && password_verify($_POST['password'], $results['password'])) {
        $_SESSION['user_id'] = $results['id'];
        header("Location: /");
    } else {
        $message = 'Sorry, those credentials do not match';
    }
endif;

After searching, I found questions and answers similar to this one, but they all were related to WordPress, and I couldn’t find a solution for Pure PHP.

Answer 1

PDO fetch returns false on failure. So you need to check this case too:

if ($results && count($results) > 0 && password_verify($_POST['password'], $results['password'])) {
    $_SESSION['user_id'] = $results['id'];
    header("Location: /");
} else {
    $message = 'Sorry, those credentials do not match';
}