What are the recommended methods for handling errors related to unknown variables in PHP scripts?

When dealing with unknown variables in PHP scripts, it is recommended to use isset() or empty() functions to check if a variable is set before using it to avoid errors. Additionally, using error_reporting(E_ALL) at the beginning of the script can help to catch any undefined variable notices.

// Check if the variable is set before using it
if(isset($unknown_variable)){
    // Do something with the variable
    echo $unknown_variable;
} else {
    // Handle the case where the variable is not set
    echo "Variable is not set.";
}