In the context of PHP and WMI, what are best practices for handling empty or undefined variables when querying processes on remote hosts?

When querying processes on remote hosts using PHP and WMI, it is important to handle empty or undefined variables to prevent errors in the code. One way to do this is by checking if the variable is empty or undefined before using it in any operations or comparisons.

// Check if the variable is empty or undefined before using it
if (!empty($variable)) {
    // Perform operations using the variable
    // For example, echo the variable
    echo $variable;
} else {
    // Handle the case when the variable is empty or undefined
    echo "Variable is empty or undefined";
}