How can PHP developers ensure that their code is secure and does not expose sensitive information in error messages?

PHP developers can ensure that their code is secure and does not expose sensitive information in error messages by setting the `display_errors` directive to `Off` in their PHP configuration file. This will prevent error messages from being displayed to the end-user, which could potentially leak sensitive information. Additionally, developers should handle errors gracefully within their code and log detailed error messages to a secure location for debugging purposes.

// Set display_errors directive to Off in php.ini
ini_set('display_errors', 0);