What are alternatives to assertions and how do they compare?

        // Example of using exceptions instead of assertions in PHP
        function validate($age) {
            if ($age < 18) {
                throw new Exception("Age must be 18 or older.");
            }
            return true;
        }
        
        try {
            validate(16); // This will trigger the exception
        } catch (Exception $e) {
            echo "Error: " . $e->getMessage();
        }