What is the function of ereg_replace in PHP and how does it differ from preg_replace?

The ereg_replace function in PHP is used to perform a regular expression search and replace on a string. It is similar to the preg_replace function, but uses POSIX extended regular expressions instead of Perl-compatible regular expressions. If you have existing code that uses ereg_replace, you should consider updating it to use preg_replace for better performance and compatibility with newer versions of PHP.

// Using preg_replace instead of ereg_replace
$new_string = preg_replace('/pattern/', 'replacement', $old_string);