How can developers ensure their PHP code is future-proof and compliant with the latest PHP versions?

To ensure PHP code is future-proof and compliant with the latest PHP versions, developers should regularly update their codebase to adhere to the latest PHP standards and best practices. This includes using the latest PHP functions and features, avoiding deprecated functions, and following coding conventions. Additionally, developers can utilize tools like PHP_CodeSniffer to check for compliance with coding standards and ensure their code is up-to-date.

// Example of using a PHP 7.4 feature (null coalescing assignment operator)
$variable = $variable ?? 'default';