What are the potential benefits of upgrading from PHP 4 to PHP 5?

Upgrading from PHP 4 to PHP 5 offers several benefits such as improved performance, enhanced security features, better object-oriented programming support, and new language features. It also ensures compatibility with newer PHP frameworks and libraries, as PHP 4 has reached the end of its life cycle and is no longer supported.

// Example code snippet for upgrading from PHP 4 to PHP 5
// PHP 4 code
$var = mysql_escape_string($input);

// PHP 5 code
$var = mysqli_real_escape_string($connection, $input);