// Example of using the PHP error index // Enable all errors error_reporting(E_ALL); // Trigger an error $undefinedVar = "hello"; echo $undefinedVariable;In this example, we use the `error_reporting()` function to enable all errors in the program. We then trigger an error by attempting to echo the value of an undefined variable. The program will output an error message indicating that the `$undefinedVariable` is undefined. Package Library: The PHP Error index is available as part of the core PHP programming language and does not require any specific package or library.