What are some strategies for handling deprecated features or functions in PHP when updating applications to PHP 5.4?

When updating applications to PHP 5.4, deprecated features or functions may cause issues with the code. One strategy to handle this is to identify the deprecated features or functions and replace them with their updated equivalents. This may involve using alternative functions or methods that provide the same functionality as the deprecated ones.

// Deprecated function: ereg_replace
// Updated equivalent: preg_replace

$old_string = "Hello, World!";
$new_string = ereg_replace("Hello", "Hi", $old_string);
echo $new_string;

// Replace deprecated function with updated equivalent
$new_string = preg_replace("/Hello/", "Hi", $old_string);
echo $new_string;