How can PHP code be improved for better readability and maintainability in tracking online users?

To improve readability and maintainability in tracking online users using PHP, it is recommended to encapsulate the tracking logic into a separate function. This function should have a clear name and purpose, making it easier to understand its functionality. Additionally, using comments to explain the code and following coding standards can further enhance the readability and maintainability of the code.

// Function to track online users
function trackOnlineUsers($userId) {
    // Add tracking logic here
    // Update database or log file with user activity
}

// Example of tracking online user with user id 123
$userId = 123;
trackOnlineUsers($userId);