function getRoleByUser($username) { // connect to database $conn = mysqli_connect('localhost', 'username', 'password', 'database'); // query to get user's role $query = "SELECT role FROM users WHERE username='$username'"; $result = mysqli_query($conn, $query); // get user's role if (mysqli_num_rows($result) == 1) { $row = mysqli_fetch_assoc($result); $role = $row['role']; return $role; } else { return false; } }In this example, we are connecting to a database and retrieving the role of a user with a given username. This function can be used in a variety of applications and libraries, such as Laravel or CodeIgniter. The getRoleByUser function is an important part of access control in any application, and is a useful tool for developers looking to create secure and efficient applications. By using this function, developers can ensure that only authorized users have access to certain parts of the application, thereby increasing security and reducing the risk of data breaches. Overall, the getRoleByUser function is a must-have for any developer looking to create secure and scalable applications.