What are some best practices for handling character encoding in PHP to prevent unexpected behavior or errors?

Character encoding issues in PHP can lead to unexpected behavior or errors when handling strings, especially when dealing with multibyte characters or different encodings. To prevent such issues, it is recommended to consistently use UTF-8 encoding throughout your application. You can set the default character encoding to UTF-8 in PHP by using the `mb_internal_encoding()` function.

// Set default character encoding to UTF-8
mb_internal_encoding('UTF-8');