How important is it for PHP developers to stay up to date with changes in the language's functions and features?

It is crucial for PHP developers to stay up to date with changes in the language's functions and features to ensure they are using the most efficient and secure methods in their code. By staying informed, developers can take advantage of new features, improvements, and bug fixes that can enhance the performance and security of their applications.

// Example of staying up to date with PHP functions and features
// Using the null coalescing operator introduced in PHP 7

// Old way of checking if a variable is set and assigning a default value
$var = isset($_GET['var']) ? $_GET['var'] : 'default';

// New way using the null coalescing operator
$var = $_GET['var'] ?? 'default';